[OKCSuburban]

If you have a BMW mech. in your area have it checked out. Any records with the car?
Check for rust, new paint or undercoating, all body lines should be correct. Look under the hood, does there seem to be some new wires....
How does it drive? Do the tires all have good wear patterns? Brakes?
Any codes or warning lights? does the top work smoothly? What shape is the rear window in? How much will it take to fix what you can see?
Go down to your Barns and Noble and see if they have a buying guide.
Search for other info too..There is a lot to check and this is a very short list.
I know nothing and can prove it.....

Best of luck.