Quote Originally Posted by 34_40 View Post
RSpears.. The SkyDrive is smaller than a pack of cigs and they do say to give it a clear view of the sky, they also "hint" that it does operate out of site and that you can test it for yourself out of view.

I've got mine under the dash so it's surrounded by the fiberglass and all the wiring and it seems to work well. I haven't selected a final location as I was going to move it to the rear package tray and test it there. If I don't see any improvement in the performance, I'll leave it under the dash.
That fits with what I've seen, and I think they "see" through fiberglass better than metal but I wouldn't swear to that. My GPS locator unit sends me messages almost daily that it has "...lost signal" sitting in the garage against the wall farthest from the windows, and in the metal barn it's a lost cause. I expect a long tunnel will be the same, but it's not a big deal to track by the tach if the speedometer drops out when blinded. They're drop dead accurate on speed.