Don't have any experience with the self stick stuff that this thread has been talking about, but it sounds like a good idea.
As far as sticking to the roof. We used the aluminum roll sheating from Home Depot comes in rolls 3 or 4 feet wide (no self stick). We applied in to the roof in a 49 Chevrolet station wagon using the 3M Spray adhesive (comes in about a 16oz can). About $ 9.00 bucks a can, but goes quite aways. Spray both surfaces, wait a few seconds then apply. It's been up on the ceiling of the wagon for about 3 years now, and there is no sign of it coming loose.
You can get the 3M adhesive at Home Depot or Lowes.
My suggestion would be to use self stick stuff on the floors door panels etc and if your worried about it sticking to the roof, use the method we used for the roof.
And to answer someone elses question here - Yeah, it makes a noticeable difference with road noise when applied to door panels, floors etc etc.
