My old car was a rental and I didn't know it. Bought it from a car dealer, with about 20000 km on the meter. It had broken suspension that I found slightly after but could be fixed while under the 3 months warranty.

The funny thing is how I found out. One day it was a very special type of frost outside. The frost crystals formed in a pattern on the back window, spelling out the name of a local gas station. Some residual of a removed sticker. It must have been a rental from that gas station.

Still, apart from the suspension problem that was fixed for free it has been very reliable.