i just recently had the starting disabled due to theft detterrent system error. after deciding i did not want to pay $300-$400 for a part that would eventually break again i decided to bypass the vats. some people say this completely disables you security system but it really only disables the resistor in your key. the alarm will still sound if somebody wrongfully opens your door.
this procedure was actually pretty simple.
check out this site....has best instructions i could find.
http://vats.likeabigdog.com