It could have been worse I suppose, keyed, scratched ... stuff that people do when they are jealous.
When I walk away from my car I always have a spotter watching and when the spotter is not at his car I spot for him. Most of the time it's a friend but I have asked total strangers that have parked close to me to keep a look out.
It hasn't been to long someone posted items got stole off their car at a show but I couldn't remember what they were. I've got security bolts on my cuda gas cap cover.