Last weekend a neighbor's car was stolen from our so-called secure condo garage (my VX has already been broken into once down there).
When my neighbor's car was recovered, the interesting thing he said is that the thieves left behind a special battery pack. The police told him the thieves use it to clip to a certain area of the chassis and send a mega-jolt which blows all the car's fuses (so the alarm won't go off). This sounds a little fishy to me -- can you really blow all the fuses from the chassis? And how would a thief drive off if every fuse is blown?
As a side note, I got a new alarm a few weeks ago, a Clifford Matrix RS3 with two-way paging so I will be alerted right away if someone breaks into my car again.