That's a hard one...it all depends how much defense you want, and are you willing to risk legal consequences.
Locking gas cap keeps sugar outta the tank, and a certain electrical device can throw quite a charge into anyone touchin it, but nothin in the world, save parkin it somewhere else - is going to prevent inevitable smashed headlights, tail lights, turns signals, nor slashed tires and seats.
I would not park it there, I would find somewhere more secure and walk the remaining distance.
-R