Screw the 120. Drop it down to 50 volts with lots of amps. The lower the voltage, the more likely it is to cause the muscles to tense and not let go.
The small town I live in has a bash of robberies last year around Thanksgiving. One house 2 doors down got hit, the day after Thanksgiving while the owners were at the deer lease. On the other side of town, an elderly couple got hit while one was in the hospital and the other visited.
I think all thieves should be beat, drug down the road, dipped in tar, feathered, and then put on public display where people can walk by and use a cattle prod on them.
I always hate to hear when someone has anything stolen. I do not have an enormous amount of work done to my truck, but it is still like my baby. It is a part of the family, just like the dog or cat in the back yard.
As for onstar, I have heard that pro thieves can disable it in under 30 seconds. Drop the glovebox, unplug the antenna, and the wiring to the module. Even with a backup battery, without the antenna there is no communication.
I hope the cops (or someone on the site) find Wendy and help return her back to the family. Should someone on the site find the worthless thief and Wendy, just tell the cops that you felt threatened when they ask why you hit the idiot with the large flashlight, wrench, etc...
