Uncle Ron-
Welcome to the CEG.
Q 1. Try Goo Gone. I have used this on the outside of the doors to remove tar and other debris with no damage whatsoever.
Q 2. I didn't use dynamat I used a much cheaper substitute. I can't speak for others, but I took the foam liner and used it as a template for cutting. I also put the foam back over my alternative dyanamat.
Q 3. Right over the wires
Q 4. I built adapters to fit the factory harness and rigged my crossovers to rest on the bottom of the door.
Q 5. No flames necessary.
My substitute was a thin floor covering from home depot. I was a carpet that would be used for a sub box. It had a rubber back on it and was easy to cut. I used 3M super 77 spray adhesive and a roller. I recently saw something that could work as well. Mechanics use a rubber sheet on the bottom of their tool drawers. This might be better. A lot of the guys here are using self adhesive roofing insulation with the brand name Resisto. Dynamat is too expensive for my tastes.
Hope that helps.
