I have the Viper 5901 and when it works I love it man, I can start the truck from within my work building when it's in the parking lot. I've had some issues with the install, truck didn't want to have an alarm installed basically LOL..so I struggled with getting it just right..long story
But here are the modules I have:
-shock sensor
-audio sensor (breaking glass etc)
-tilt sensor
-auto start
-one-touch window modules to roll windows down
-mini-piezo inside the cabin (ear piercing in case they get inside the truck)
-backup battery/siren
I think thats about it, almost all the modules you can install I think. They've worked flawless when the install itself is done right.
HTH
B