People like that piss me off. No respect for other people property. Is it just in the clear coat or is it deeper?
Depending on your situation, I suggest putting a high quality wifi cam or webcam on your car and use a service like ugolog.com. I've caught somebody that stole the head unit out of my Acura before this way. It's great peace of mind and it's cheap, and nothing is better than sweet sweet revenge.
As for the scratch... If it's past the clear coat, you'll obviously have to touch it up. Call up your Lexus dealer and see what they say.
I parked at the end of the row and the side that was scratched is the side which was not next to any car. I assume it was someone walking by who had nothing better to do!Were did you park at. I try not to park next to anyone at all times.