I'm sure there are better threads but I thought I'd pass along what I just learned. My 92 RS came with some type of aftermarket alarm. The obvious signs were a small red LED on the dash and a huge horn mounted underhood, small toggle switch and a push button on the fuse panel surround. Looked like a dealer install. I wanted this stuff OFF the car. I reacqauinted myself with the joys of laying face up under the dash to do work.


Except for the small wires going to the light, switches, alarm modules and siren the main wires were solder tapped and taped into the ignition switch harness. The wires that were simply tapped in I cut short and taped off. The wire that was actually interrupting a circuit (yellow in the Chev Harness) had already been reconnected to itself (effectively completing the circuit but with about a foot extra length). I used the spade connectors that were already on that and connected them to a switch under the dash - poor man's alarm that might deter the casual thief (maybe not).

Anyway, bottom line - for most of these alarms you can rip everything out as long as you re-complete the main ignition circuit that the alarm had interrupted. I couldn't believe the pile of crap left on the garage floor.
Might be enough copper there to recycle and buy me a cold one.