If you could prove that it was installed incorrectly to the shop'* owner or manager, the best you might get is a refund for the installation. Unfortunately, I still don't think the shop has any legal liability if the car is broken into or stolen. It could certainly hurt their reputation if word got out (how about a Letter to the Editor in your local newspaper), but it doesn't seem like suing is a viable option. Call the owner/manager back and politely inform him of these options, and see what they might be willing to do for you.

hey man atleast your ride didnt look like this after it was stolen

before::






after:

I did ask politly for a refund of the whole system and denied my offer!

the GM pass-key theft deterrent system is a JOKE.
it can be defeated in under 30 sec. with a pair of pliers
NO KEY NEEDED.

ROD