Edley,
I spent almost 3 years as a valet a fancy restaurant in downtown Philadelphia while in college (and I graduated in '97, so it wasn't
that long ago). I can't honestly say in all that time we had a Cobra pull up. Lots of Porsche, Ferrari, Rolls, etc... Usually they let us park. Many times they would hand us money to leave the car up front (though we kept the keys, in case the cops made us move the cars), but a spot up front cost $10-$20. I suggest giving the valet a few bucks and asking to park it yourself. They'll understand.
I can honestly say that of the thousands and thousands of cars I parked, I didn't damage a single one (not that I didn't sample their power, I didn't damage any of them), but many of my fellow co-workers shouldn't have been trusted with a tricycle, let alone a $50,000+ car.
Steve