I just installed a Viper unit in my hybrid and Denali. The newer remote start/alarms have a load more features and what not then the original in the TB and early GM's. I have the 2 way communicating FOB, remote start, door lock/unlock, hatch/trunk release, rear defog activation from the fob, turbo timer, delayed exit dome light. The domes go on when unarming, and a few others.