Found this MSNBC article relating the mysterious disappearance of "Honky", the technically un-stealable Honda Civic. The story is interesting, and has this nifty bit:

The new technology [of factory-installed anti-theft devices] has had a demonstrable effect on car thefts. The Highway Loss Data Institute reports that factory-installed immobilizing antitheft devices reduce the stolen car rate by 50 percent. “It doesn’t go to zero, because you still have the ever-popular method of rolling cars onto a flat-bed truck,” says institute president Brian O’Neil.

We went on record a long time ago on the uselessness of aftermarket car alarms. Take the keys out, lock the doors if you have to, and spend the extra cash on something else.