How to stop valets abusing your car?
I've always been slightly annoyed by returning to my car or having handed it back and finding that the aircon, radio and seats have been messed with but always kept it to myself as I appreciate that these guys, especially at airport valet parking, have to turn things around quite quickly and some pillock like me moaning about first world problems just makes a bad job harder to take. I've never had a valet actually damage my car so I shouldn't complain about that stuff.
However, I recently got a new car that, while not an actual supercar, is pretty quick and infamous for being fun to drive.* Recent news reports in the UK revealed that airport valet parking employees have been joyriding in customers' cars and I don't want it to happen to mine.
My question is, does anyone have any methods to rein in this kind of behaviour, or track it so that it can be reported later?
*Before anyone jumps on this the car isn't brand new by a long chalk so no, I'm not just using this as a forum to show off my new car.