> This stuff is just flashing tape.
>  Right?

Flashing tape is generally a 2"-3" roll of 20mil plastic backed
bituminous adhesive. Peel & Seal is a 45mil foil backed roofing
material available in 6", 12", 18" and 36" rolls. The original Dynamat
stuff was (if I recall correctly) the same foil backed adhesive stuff,
but only 40mil.

> It's not a sound deading material as Q-Pads or any other " In the door,
> or  interior panel" material is.
> Right?

It doesn't work so much as a sound deadener as it doess a vibration dampener.

> It's just basicly a vapor barrier.
> Correct?

It's actually more of a general under-roofing material. Mostly used
under tile for ridge lines or valleys as a flexible seam protector.
Also very popular for quick-fixing mobile home roofs, it seems.
>