Buying an ex-rental car could be a good way of saving money. They're often not very old, will still be covered by the manufacturer's warranty and will have been maintained very well. Some of the big hire car companies will check things like the tyres pressures and oil levels on a weekly basis – that can't be said for many privately owned cars. Of course, some drivers might have driven the car hard, but that could be true for ex-PCP or fleet cars, too.