When I bought this car, I paid $250 for it. It was about one step away from the wrecking yard! The interior was a mess, one of the doors had a big dent in it, and nearly nothing worked. The car would not start. The previous owner was using it as a commuter car. A radiator hose went bad, and he overheated it on the freeway. He thought he had ruined the engine...
Diesels (especially the little VW diesels) need to get REALLY hot and stay hot for a REALLY long time before any serious engine damage is done. Turns out all the car needed to run/drive was a starter. A friend of mine is a serious "A1" (the first water-cooled models, like Rabbits) VW guy, and he had a starter. We put the starter in and it fired right up!
As I said, the car needed a LOT of work so I had to source a lot of parts. I was fortunate enough to find a low-mileage gas-powered '82 Jetta with a blown motor. I bought it for parts for my diesel. Same color and everything! So I replaced the damaged door and a few other body panels for aesthetic reasons. Also cannibalized from the '82 were the carpet, some dash parts, seats, struts, and other miscellaneous items. Got the car looking pretty decent.
These are pretty well-made little cars (all early Jettas are made in Wolfsburg, West Germany), but remember the newest one you will find of this type ('80-'84 here in the States) will be 23 years old. In addition to the above items, I tried to "catch up" on a lot of the maintenance that had been left undone over the years, including:
Cam, front main, and intermediate shaft seals.
Passenger side motor mount (these are a NIGHTMARE to change)
Windshield and gasket.
Rebuilt the shifter.
Rebuilt the vacuum pump.
Intalled a decent stereo (Blaupunkt)
Replaced valve cover gasket.
Repaired the odometer (ask me how?)
Overall, I probably do not have more than $1000 into the car, but I was able to do all the work myself.
This little car has three really nice things going for it...simplicity, reliability, and INSANE MPG. The mileage I get with this car is just ridiculous. I get a no-BS 46 MPG in town! With only 52 horsepower, this car is not going to win any races. Seriously. But I get nearly 500 miles on a 10.5 gallon tank. I haven't taken it on the freeway, but I know this car has a very tall 5th gear. I have been told by most who own one of these to expect 55-60 MPG on the road!
But these cars do have some common quirks. The windshields tend to leak, right above the fuse box of all places. This is because the windshield is not caulked in like on most cars, but rather uses what is essentially a large rubber o-ring gasket for a seal. After 25 years, the gasket shrinks, cracks, and begins to leak. New gaskets are easily available, and not too expensive ($70). Any glass shop can do this. The rear window is sealed in the same way, and has a lot of the same problems. If your trunk is leaking (as mine was) this is the culprit. I just found the leak and dabbed a bit of silicone sealant on it.
These cars also tend to have fluky electrical systems, and most of the problems center around poor connections in the fuse box. The A1 Jetta/Rabbit uses the old Bug-style open porcelain fuses, and these can corrode on the ends, causing open circuits. I had this problem on my horn, left low beam headlight, and brake lights. Just remove the fuses and clean the contacts. Should take care of the problem. If your fusebox has serious damage from water/corrosion, replacement boxes are cheap and easy to get/install.
Rust can also be an issue... find a nice one from the Pacific Northwest or Southwest.
These cars are pretty light, so they handle well. Brakes/tires also benefit from the lightness of the car... expect them to last a long time after they are replaced. There is VERY little that can go wrong with these mechanically, as the diesel engine is VERY simple. Unlike most new cars, which are full of sensors and electronic junk, diesel Jettas and Rabbits have nearly no engine electronics of any kind. An alternator and a starter...that's about it.
They are not the most comfortable car, but are not particularly uncomfortable either. As with most German cars, the ride is...well..."firm". And the diesel engine can be a bit choppy at idle. If it is really bad, then chances are the passenger side motor mount is bad. THESE ARE VERY DIFFICULT TO CHANGE.
If you can find a nice one, an A1 diesel-powered Jetta or Rabbit makes for an excellent commuter. They happily run on biodiesel, and can be converted to run on WVO/SVO as well. Plus, they are still cheap. But that is changing as word about these little cars spreads! They are spartan, but simple. VW sold a lot of diesel Jetta/Rabbit models in the US during the gas crunches of the late 1970s and early 1980s, but as gas got cheaper again in the late '80s and early '90s demand fell off. A later diesel Jetta may be a little more comfortable, but they are much heavier and harder to find. If you can find a nice A1 diesel Rabbit, Jetta, Dasher, or Pickup, GO FOR IT. You won't be disappointed. The turbo models are particularly nice, as they offer a needed horsepower boost. Low maintenance/high MPG!! Small displacement diesels are the wave of the future...