[duke36]

One product that may emulate the original tarry substance found in some A inside panels
would be 3m Body shutz spray undercoat . One can get a $15 undercoat gun that fits on top of the bottles of it from Amazon or others and add a plastic extension tube if desired. Stuff drys hard and is waterproof. The foil based insulation that many use can absorb/ retain water especially in cars with operable windows and cowl/rear panels where water drains out thru weep holes, etc. We don't buildup material at the bottom sills around the holes, etc.