There was the remains of an aftermarket alarm/start system spliced into various underdash harnesses on my Burb when I got it. Intermittent Cruise not working/disengaging was traced back to a module T-tapped into the brake switch circuit.
Living here where we get real winters, the thought of remote start has always appealed to me, but the interfacing of an aftermarket remote start system with a diesel's need to activate the glowplugs and also WTS accordingly leaves my leary of finding a system that will work correctly.