I've been pouring over vehicle anti-theft, anti-jacking tech and trends for a few days now and it's looking really bleak actually. The would-be tech that may make a difference is being outsmarted by thieves with hi-tech gadgets that mimic your car-key signal and opens up the car without any effort on the part of the thief. The usual physical locking methods are easy to detach, alarms are pointless, wheel-locks do little.
I did find the 3M window film that slows down a jacker... that is to say, if they keep at it they will get in, but it takes quite a bit of whacking to actually gain entry to a car. This buys you precious seconds to put the car in reverse, turn the wheel away from the attacker, and hit the gas. WHACK! THUD THUD!
Short of electrifying the car (remember Robocop?), those bastards can get away with anything. That said; having a low-profile car, having several layers of security makes a car less of a target and the thief moves on to an easier target. Let's face it, their thieves because they don't like to work hard so present them with something hard to do.