My understanding is that those break-in's were vehicles parked in side of the fair grounds. The jerks were watching for people taking things to their cars and then going back in. I would suggest that you leave nothing in plan sight and take it out when you leave.
I parked out side in the gated part across the street, notice many cops in the street, but did not see anyones car broken into. Just make sure you don't leave anything in plain sight, or leave anything in your car at all!
I agree, just do not leave anything in your vehicle that is worth stealing. I would hate to see you miss going to a gun show because a few idiots cant act right and would rather steal than work. Most know that you cant have loaded guns in the show so they assume there will alot of guns left in vehicles.