I just recently bit the bullet and pulled my dash. My dash would get the super annoying, super loud squeak when it got hot. I first put some rolled up cloth to jam against the windshield and the dash. That fixed the squeak 90% of the time but on really hot days it got bad.
Fast forward to a few weeks ago, when I pulled my dash, you could see where the dash would rub against the black rubber part that runs up the side of the windshield. There were "Shiny" marks on where the two would meet and rub. So I put a few bits of sticky back felt where I saw the shiny parts (and there were rub marks one of the AC ducts directly under the center of the dash) and so far, I'm squeak free. I took it to a bogus Auto-x and man was it hot on the way home and no dash squeaks.
Lastly, the reason I never wanted to pull my dash was because of those passenger side air bag clips. I don't know if we can still get them or not but I just reattached my PS airbag cover with some high temp velcro I found at homedepot, hopefully it holds. I just wished i pulled my dash sooner.. Now if I could just get rid of that last squeak from the hard top..
06 Exige (now rev300 powered!)