The amount of wear and tear put onto a rental car makes it unlikely to be a low maintence or reliable car. People who rent the car usually do not treat it like their own and sometimes act as if the car is a race car. I bought a used rental car myself for very cheap, and it lasted just as long as a one-owner car would. You have to expect a little more wear and tear, but you can also expect it to be a newer year for the price, so it evens out/