* Inside the Driver's Side door frame (or in the jamb next to the latch).
* Top front center edge of the dashboard visible through the windshield.
Light Trucks:
* Left front door latch post.
* Top of the firewall near where it meets the windshield (under the hood).
Heavy Trucks:
* Right front frame rail, visible through a round hole in the cross member.
* In the cab on the driver's side B pillar.
