Thanks everyone for your advice. I'll look for an aftermarket alarm.

Anyone? When I was looking at a Vibe the Pontiac dealer thought they could put one in, but after the purchase they said it wasn't possible. I have a GT loaded.

Has anyone added the Toyota Matrix alarm to a 2006 Vibe GT? I found the Corolla/Matrix instructions online but I'm not sure if all the wiring is the same in a Vibe.