In reply to Dave Garnett:
We discovered a deep scratch that had been touched up with paint after we gave our hire car a wipe down on arrival at our rental property in Corsica last year. We'd missed it on first inspection. We were a bit nervous of getting stung for someone else's subterfuge on returning the car to the airport. I went so far as to buy some polish to improve their botched repair and inspected it daily in the hope it would somehow merge into the paintwork. I'm pretty sure we threw some dust over the car shortly before arriving back at the airport to hide the mark.
It was with some trepidation that we faced the eagle eye of the hire company inspector. Instead, an 18 year old boy simply grabbed the key, checked the fuel, hopped into the car and gunned it across the lot and straight into the back of another car. We stopped worrying around this point!!