My Compustar it tied into both the rear door (added a pin switch) and the rear door opener (for the popper mod). When I click the second button, it disarms the truck. When I click the third button, it both disarms the truck and activates the trunk popper, so the door opens. It also has an auto-start and feedsback into the remote up to 6000 feet (I have the spread-spectrum version). When the alarm goes off the remote does too, with a small LCD showing whether it's a door, trunk or window breakage/shock. When the truck is remote started it shows lights on and exhaust coming from the rear.

There are two optional buttons that I could tie into opening/closing the windors or sunroof, or even the stereo if I wanted.

-- John