When buying an old, used car the most important characteristic is condition. Fixing up an old car can cost a ton of money so unless you buy it cheap enough and can do a lot of the work yourself, my advice is to always buy a car in the best condition you can. Just about anything else can be changed but the more expensive things are the interior and the transmission so you should try to get the car you want with those at least. If you don't know what you are looking at, ie, you don't have a lot of mechanical experience with cars and Deloreans in particular, you should get someone to help you examine the car when you are ready to purchase it. Get in touch with local owners. They can offer a lot of assistance. Don't buy the first one you see and don't buy one just because it is local. If you take your time there are plenty that come up for sale and by then you will have learned what to look for.