I run a viper alarm, I have for years, they are great. I'm MECP first class installer and like they way they work. A battery backup unit (viper 520) will monitor the vehicles voltage and set off the alarm instantly if the battery cables are cut. But if someone wants it bad enough they can circumvent any alarm. I run a GPS unit that gives me access to the viper app that can alert my cell phone if my alarm goes off. I can also start my truck from any location. It's a nice feature when you're out of the 1 mile range of the alarm fob. The GPS feature is a service that costs about 80 a year but for me it's well worth it.