head unit (seat belt/ air bag). The HID is good that way, loss of traction, icy conditions, low gas, etc. The chimes usually just alert me to to look at the HID anyway. I kinda miss the lane change clickers, but that's about it.
That's too bad about the fuse. I originally took the voltmeter to all the fuses, and that's how I found it. Another alternative is sunroof. Even though I don't have a sunroof, it is fused and active, and follows the same characteristics as the WndwRAP line.