Thanks for the feedback, your horror story about the rivnuts is one of the things that has me re-thinking installing these.

Does anyone know what size the rivnuts are? I'm thinking they are probably 1/4-20 (or metric equivalent), but the pictures I've seen look like they could be a bit larger.

Are the ones that come with the kit blind bore (makes sense to me since you wouldn't want water dripping through them).

 

I think I've decided not to mount them. In all my research I've been seeing marker lights mounted flush on the roof, and I think I want to do that instead. I'm actually considering my wife's opinion, as she says she doesn't like the offroad lights. Here's info I've found if you haven't already:

Screw covers are 19153917 (should be package of 6)

Switch is 88963884

Pigtail for switch is 12101864

All three parts available from dealer (or online parts - about $60+ shipping).

The pigtail isn't a complete harness, but should be easy enough to extend and wire it.

Only thing I didn't source is rivnuts, but install I saw indicates a 9mm drill is used, so that should make it easier to size rivnuts.

Good luck.