When I pulled my carpet I found that in addition to the asphalt-like sound deadening, there were press board like panels with foam backing that covered the driver's, passenger and parts of the tranny tunnel. The press board was slightly worn through, damp, moldy and heavy and there was significant rust through in the driver floor pan area that may have started from under the car but wasn't obvious until the "insulation" was removed. There were asphalt pads under these as well but they were not in good condition and no longer functional.This is in an 02 that has spent it's entire life in California. After 12 hours and trying different methods, I found that warming the asphalt with a heat gun and using pneumatic scrapers and wire rope brushes on an angle grinder made it simple. Probably would have taken 3 hours in total had I started with these tools rather than trying elbow grease for as long as I had. I'm glad I removed it all. Yes it was a lot of work, but I am now confident that my floors have been properly repaired, POR'd, and sound proofed.