See photos. I want to drill into the top of the B and C pillar. I think all the wires are routed on top of the pillars and none are in the body frame, but I wanted to be sure. I read somewhere there is an ultrasonic shatter sensor somewhere in the B pillar?

Loc 1: top of B pillar where that bracket hangs
Loc 2: Top of C pillar where it meets the upper frame rail

 

The sensor would've been mounted on the trim, not within the structure.