It's a real roll of the dice when buying a salvaged car. If you're buying it from the person who rebuilt the car, then ask for a complete set records (including receipts) covering what was repaired/replaced. Often, they have to show this info so the car can pass inspection to get a rebuilt title. Take this info and have the car inspected by a mechanic. If there's no records, then I'd pass because there are too many unknowns. You're just one major repair away from this not being a good deal.