I always tip $5 with my wife's RX because I thought that was standard at nicer restaurants around Pittsburgh. However, like zzzzdoc said, if I have my LS or Range I will tip $10 or $20 which is definitely worth it to avoid damage. Also, I always tip when dropping off. Some people wait to tip on the pick-up but by that time the car has already gone through valet hell.

 

I believe the story from Luxury1 AKA Pompass A^* Hole to most of us, That it is not really the Valet but it is probably the Customer with the attitude that get's his car beat up. If you treat them nice and throw a couple bucks at them when entering they will show you the respect that most of us deserve, there is a reason why they drive Looser1's car in that manor.