Sorry, but you've got to read the first post on this thread. I did buy a tilt away, and it sucks...that's precisely why I'm having this discussion about drilling holes in the roof.

 

After deciding where to position the tracks, I marked the hole positions, then just drilled the top, but not through the channel on the inside.

I filled the void with the foam from the top. After it dried, I re-drilled, this time through the new top hole, the foam, and then through the inside channel.

Here's a couple of suggestions:
I taped the seams of the underside in case the foam leaked through. As it turned out this wasn't necessary, but I'd suggest it just in case.

The Thule tracks only come with enough machine screws for every other hole. I bought extra SS screws and bolted every hole. I had shortened the tracks by about 6".

Lastly, practice with the foam. I over filled a few areas and it took a long time to dry, and I had to keep wiping the excess that was bubbling up.

All told, I'm thrilled and it's extremely sound, I think with, or without the foam, but I like the concept.

 

I think this is exactly what I'm gonna do! Thanks so much for the info. I think I may fab some aluminum strips to mount on the underside too, just for a little added protection.

 

I remember seeing pictures from a member that drilled large (1.5") holes on the underside channel, as access for a socket wrench. He then bolted to the single top layer.

This might work for you if you can "fish" in your metal strip.

You don't want too much "stuff" on the bottom of the edge channel. It's a very close to the roll bar fabric, at the passenger seats.
note the row of machine screws...


Start drilling!!!

 

I have Yakima Tracks and Qtowers. It requires a little modification but I like it for my rack set up. Rattles a little bit with Freedom Top panels off. I mounted the tracks on the back of the top and they come to just where the freedom top panels come off so I can still remove the panels. I want to do the sport bar mounting kit for the summer.