I've sailed there a lot and never had a problem, even sailing till really late. I definitely make an effort to hide/cover anything worth stealing as a deterrent. As said above, there's always a lot of auto glass in the carpark. If Seabreeze shows green arrows, the carpark will be pretty full so its a bit safer.
Keep an eye out for those marginal "yellow arrow" days when the seabreeze actually comes in - you might score it to yourself!