I know nothing about this system, but this link (compliments of Google) shows this dealer selling the KARR for $695, so if you only paid $250 and it is the same thing, then it was a good deal.
http://www.folsomlakescion.com/scion-protection.htm
But... I do not know what it adds over the built in alarm system in the twins. My understanding is that if you enable the factory alarm system and your doors or trunk get opened, the alarm goes off.
