One of the great things about the Bangernomics philosophy is that you can afford a far bigger and more luxurious car than you would be able to choose if you were buying new, or nearly new. Leather seats, power everything, air conditioning and enough room to transport four Scottish surfers and all their kit from Inverness to Newquay - all for little more the price of a year's servicing on a small family hatchback at your unfriendly local main agent. Big old cars (except for Mercs) are deeply unloved by the punters right now, and if you can live with the petrol bills and higher insurance, you could soon be driving an ageing but comfortable luxury tank with years of life left in it.
A few general comments. Many big old cars have air conditioning. Very few have air conditioning that works. In the British climate, a/c is only useful for about two weeks each year, and for the rest of the time it is left switched off. It doesn't take kindly to this treatment, and usually dies expensively. So unless you have recent bills for a full overhaul, just think of the system as decorative. All those extra controls look really cool, but they probably won't do anything.
Big heavy old cars give suspension and brakes a tough time, so listen for unusual clonks and groans, and once you have bought the car, give the braking system a good check over - budget to replace front discs and pads at the very least, unless they have just been done. All these cars have power steering as standard - leaking racks and pumps can be expensive to fix, so check for fluid leaks, and wind the steering from lock to lock to see if the system makes any expensive noises.
Electrical toys - sunroof, windows, mirrors and possibly even seats - are great if they work, but a real pain to fix if they don't. Your average ten year old luxobarge has enough cabling to rewire the London Underground, and it will be starting to decay. Learn how to read wiring diagrams, and buy a multimeter, and reduce the chance of future aggravation by ensuring that all the electrics work when you buy the car. It's worth checking the fusebox and ensuring none of the fuses have been bridged with nails or silver paper.....
With all the health warnings out of the way, check out these awesome executive expresses:
Audi 100 (1983-90) Bland but highly aerodynamic shape makes for a refined and economical motorway cruiser. A bit short on luxury toys, but comfort and durability make it worth a look. 1.8 is underpowered (it's the same engine as a Golf GL), five cylinder motors much better. Cambelt changes are crucial to avoid expensive damage - and not really a DIY proposition on the five cylinder cars due to need for special tools. Diesel tends to crack cylinder heads with age. Galvanised body, so rust will only be a problem if car has been in a major shunt. Not brilliant for DIY, but most jobs are possible with patience. Cheap parts from VW-Audi specialists. Avant estate is not really a Volvo-style load carrier, but useful nonetheless, and attracts a significant price premium over the saloon. Quattro versions rare but worth seeking out. 200 Turbo very quick, but scarily complex and likely to end in tears.
BMW 7-series (1977-86) Favoured transport for a generation of pub landlords, but also popular with dealers in recreational pharmaceuticals. If you can live with the image, you get a lot of car for your money. Engines (all six cylinder, from 2.8 to 3.5 litres) are strong, but burn oil at high mileages - check for exhaust smoke, especially on overrun. Rust not often a problem, but be suspicious of cars fitted with chrome wheelarches - these are most often hiding rotten bodywork behind. BMW specialists can supply most parts at reasonable cost, but sooner or later you will be landed with a big bill, most likely from the engine management system. Many old BMWs have metric tyres, which are big bucks to replace. If the car runs smoothly, drives well and doesn't have holes in the body, it's probably worth a punt, but walk away from anything less.
Ford Granada (1985-94) Probably the easiest big banger to find - these sold in large numbers, and the range was huge, from poverty spec 1.8L to the fully-loaded 2.9 Scorpio, in saloon and hatchback body styles. Wide range of motors, but only the V6 is really up to the job of hauling all that metal around. ABS standard across the range, so make sure the warning light behaves as it should. Rust usually attacks rear wheelarches first. Rear suspension can sag badly on heavily abused workhorses, causing the wheels to splay out at an odd angle. Excellent parts availability and below average insurance costs, but can be unreliable as it gets older - build quality certainly not in the BMW/Mercedes class. 4x4 version makes a superb towing car for very little money. Go for the highest spec car you can find - anything less than a 2.4 Ghia misses the point.
Jaguar XJ6 (1968-86) One of the most dangerous ways to blow £1,000 known to man. Gorgeous William Lyons - styled body hides rot-prone inner structure and mechanicals that almost defy DIY maintenance. Early cars now acquiring classic status and prices to match, later Series 3 (1979 on) has fuel injection which goes expensively wrong. British Leyland build quality - these cars rot badly in unseen places, and by the time the holes appear on the outside, there isn't a lot of inner structure left to weld patches to. That said, a well-cherished 4.2 (with leather seats) will give you the most opulent driving experience this side of a Bentley, and home maintenance isn't impossible armed with a good workshop manual and comprehensive set of tools. Engines are strong - look for oil burning and low oil pressure, listen for timing chain rattle. Auto transmission wasn't built by BL and is usually the least of your worries. Fuel consumption ruinous, and consumables (tyres, exhaust etc) expensive. Think of your £1,000 as a down payment - much expense is likely to follow.
Range Rover (1970-96) Rare example of a car that completely missed its target market, and went on to be a huge success anyway. Originally intended as a utilitarian farmers workhorse - vinyl seats, rubber floor mats etc - but got rapidly more luxurious from the late 1970s onwards. 3.5 litre Rover V8 often replaced with some kind of diesel, from Perkins tractor engines to Jap six-cylinder turbo motors. Fuel consumption in petrol form even worse than an old Jag, but plenty of space to put the tanks if you want to fit an LPG conversion. Separate chassis is easy to check for rot, but body is an unholy mixture of mainly aluminium panels on a steel frame, and tends to get eaten away wherever the two meet. Check sills, door pillars, floors, inner wheelarches and seat mountings. Later Vogue models have fuel injection which can lead to all sorts of problems - stick to carbs for reliability. Needs careful inspection and decent mechanical knowledge to avoid buying a dog, so do your research carefully.
Mercedes W123 series (1976-86) The classic Stuttgart taxi - a bit too spartan to be a true luxury car, but peerless build quality and durability, combined with the sort of image which means you can get away with driving a twenty-something base model with 250,000 miles on the clock, without your wealthy neighbours looking down their noses at you - they'll think you inherited it from an uncle. Indestructible interiors make this a prime candidate for 'clocking', so check very carefully for mechanical wear and tear. Not immune from serious rust, whatever the vendor may tell you - check sills and floor for signs of trouble. Estates enormously useful but hard to find at a sensible price. Parts cheaper than you might think, thanks to independent specialists. 200 Diesel has the same power output as a 1958 Land Rover and is best avoided, 230 petrol is probably the best compromise between power and running costs. A nice old thing to smoke around in.
Peugeot 605 (1991-98) Never really popular with British buyers, and now heading rapidly into the twilight zone reserved for old French luxury cars. Crippling depreciation means you stand a chance of finding a tidy example for under a grand. Mechanically conventional, so few horrors await the DIY mechanic. Four cylinder motors seem to take up smoking quite readily, and electrics are built down to the usual French standard, so check all the accessories work (and many of these cars started life as dealer demonstrators, loaded down like a Christmas tree with toys). Swift, anonymous transport for the introverted.
Renault 25 (1984-92) Another big car from France that failed to sell over here. Lovely old comfy sofa of a motor car, with big squashy seats and lots of buttons to press. Not all of them will do anything - resist the temptation to open electric sunroof or windows, unless you are sure you can get the car back under cover before it rains. Some DIY jobs can be tricky (as with most Renaults). Large range of engines, all adequate for the task - rare V6 Turbo is frighteningly complex and probably best avoided (although worth buying if very cheap, as the powertrain is popular with kit car builders). Practical hatchback body, but a bit cramped in the rear seats unless you can find one of the rare long wheelbase versions. Paintwork not the best quality, and older cars can look very shabby even though they are structurally sound. Specialist support not as good as for German luxobarges, and some parts may be hard to find anywhere. AA membership definitely recommended.
Rover 800 series (1986-91) Oh dear. If you need to understand where it all went wrong for Rover, the 800 series explains a lot. It looked promising on paper - basically a lightly-reskinned Honda Legend with a hugely useful hatchback option and a choice of brand-new four cylinder motors and silky Honda V6s. Sadly the build quality on early cars wasn't really up to scratch. Electrics are particularly troublesome, and poor paintwork allowed rust to develop at a fairly early age. This is often just cosmetic, but who wants a luxury car with brown blotches on the doors and wheelarches? The end result was that used prices crashed to the floor and stayed there, so a clean, well-loved example is a real bargain. V6 probably the best luxury bet, and Vitesse version is an under-rated Grand Tourer in the old Rover mould. Four cylinder engines a bit gruff and prone to oil leaks, but very durable. Post 1989 cars had much better build quality all round. Later Series 2 cars are now appearing in the sub-£1,000 price range, and have nicer interiors (and a chrome grille). Lots of information and support on the Web for these cars. Reader (and Rover owner) Chris Costello tells me that steering racks tend to fail at around 100K and are a pig to replace, rear brake discs need a special tool to wind back the pistons in the calipers, and that timing belt tension on the four cylinder cars is critical and best left to professionals.
Saab 9000 (1985-95) A worthwhile rival to the Audi 100 or any of the Ford / Vauxhall / Rover offerings, especially in capacious hatchback form. All go well (especially Turbos) and handling is far more agile than one would expect from a car this big. Most cars well equipped with bum-warmer seats and usual electrical toys. Saab was an early pioneer in DIY-proof electronic engine management, so beware of anything that doesn't run properly - don't count on being able to fix it without professional help. Turbos need regular oil changes, so beware of anything without a service history. As with German cars, specialist support is excellent, which keeps parts cost down. These cars tend to eat front tyres, especially the more powerful versions. Reliability generally less good than the best of the Germans - electrical gremlins and the occasional major mechanical failure, but it's hard to point to any specific fault to look out for.
Vauxhall Senator (1987-93) Underrated rear-drive luxobarge, with bombproof straight six motors and plenty of luxury fittings. 3.0 24 valve is crushingly quick (204 bhp) and was very popular with the police, so be suspicious of apparently low-mileage cars in white, especially if they appear a bit short on toys - they may be recycled motorway patrol cars with big mileages under the wheels. All the usual advantages of buying a popular car from a mass-market manufacturer - affordable spares, reasonable insurance and a simple enough DIY proposition. Bodywork fairly durable, tends to go flaky around rear wheelarches first. Senators have a loyal following, and surprisingly few turn up in the Auto Trader. A future classic? Probably not, but a nice old thing to own, and way better than the Omega that replaced it.
Volvo 740 / 760 (1984-92) Strange angular styling followed American fashions of the time, looks just about OK as an estate but decidedly odd in saloon form, which keeps prices of the latter well down. Not really a luxury car, but upper-end GLT and Turbo models are comfortable and heavily laden with goodies including leather seats. Rugged and good for big mileages if cared for. Rust only a problem on badly neglected cars. GLT Turbo Estate is really the only choice out there if you want a luxury load carrier at this price level, and don't fancy a Range Rover. Good cheap parts availability through specialists, and few quirks to put off the home mechanic, thanks to simple rear drive layout and plenty of underbonnet room.
Finally, a few less likely punts. Citroen XM - looks awesome value, but an electrical disaster area. Peugeot 604 / Talbot Tagora - square rigged French luxury cars, now on verge of extinction and getting hard to find parts for. Alfa 164 - early high mileage cars now cheap, but DIY tricky and running costs likely to be steep. Rover SD1 - mostly rusted away, but worth hunting out a good 3.5 Vanden Plas or Vitesse. Nissan Maxima - inoffensive, reliable and hard to find, makes a brilliant minicab. Ditto Honda Legend - basically a Rover 825 with better build quality. Or for the extrovert, there are a fair few cheap old American cars out there - Cadillacs, Lincolns and the like. Left hand drive, and Halfords won't stock the parts, but if you want a real luxobarge, a late 1970s Lincoln Town Car is hard to beat.