it has to do with your rear view mirror, the cars with the compass have a different rearview mirror on the inside. if you dont have it, it wont work. go look in a wrecking yard for the bulky looking mirror. and wire that attaches to it should already be in your car, if you can pull the headliner down a hir, right next to the windshield, it should be tucked away in there. thats how it was on my 90 sig. that didnt come with the compass mirror.