Thanks for the responses. Something I should have clarified is that I dropped the car off after-hours and they called the next day. As hard as it is to believe, I am not exaggerating -- when I was taking the pictures a few customers in the waiting area overheard my dealings with the manager and took me aside to say I was right -- no damage.

I *think* they dropped this -- the manager promised I would receive a call promptly at 8:30 and they never called -- and this afternoon the $300 hold was removed from my credit card and they charged the originally-agreed-upon $93 for the weekend.

I am still rather disturbed about this business practice -- I wonder how many unsuspecting customers get stuck with the bill. And because there isn't even a dent THERE, I can't even say "well next time I'll inspect the car more carefully." Not very comforting!

Thanks again for your responses.