Handing over your Cobra keys might make you cringe if you've ever seen the movie "Ferris Buellers Day Off"...... I can't forget the moment the Ferrari got into the hands of the valet guys for a very spirited joy drive.
I've never done it, but I did pull into a hotel entrance once to pick up someone and the valet's eyes looked like saucers!
Well, if I ever get into that situation, I think I would politely ask if they would allow me to park the car myself and tip the valet anyway. Depending on the hotel, I'm sure some valets have parked everything from Lambos to Ferraris without the owners even blinking an eye. I might come across as a jerk, but I can't afford to redo the car or deal with an insurance fiasco is something truly did happen to the car.