Compustar 2W900FM-AS
I remember reading someone doing a test with this alarm vs. a viper 791xv. Both cars were in a mall parking lot next to each other. Both walked into the mall, the viper 791xv lost communication with the car 100 ft into the mall while the compustar lost communication at 1000 ft.
Either way, install is the most important thing you can do to protect your car. Hide the brain away(not under the dash), an extra battery, get power directly from the car battery and not a wire under your dash, extra piezo sirens everywhere, glass sensor, etc etc...