Add to E30 buyer's guide
Make sure that you check the car with a full tank, I bought my car and the whole time it only had less than 20L in it. Get it home, fill it up, alas!! it is leaking. From what I see it is very expensive to replace the tank and alot of people have had pacth jobs. I highly recomend you inspect the lines on the drivers side just in front of the rear wheel.
Oh yeah a replacement tank ordered from germany is 943.00 cdn (at cost) from BMW so I was told.