When you arrive, make sure the engine is cold. Check all the fluids. If there's milkshake in the radiator or the dipstick, that's a no-go. if the trani fluid is dark and smells burnt, that's a no-go. Start it. If it's hard starting, maybe pass. check the paperwork, make sure the VIN matches and that the title is clear. I've never had an issue with a car that had a reconstructed title, but also I've only bought cars older than 2000, because fuck modern cars