Also do I need to pull off the mass backing material from the carpet prior to pressure washing?
I found my water leaks, first one is third brake light and possibly a little bit of the bottom of the rear window seal (hopefully just the brake light). Next the two plugs in each rear corner of cab between it and bed is leaking in a little. I think the drivers side front leak is the door seal since and the passenger side appears to be the glue holding the heater box on the firewall appears to have one spot that is dripping.
On the soundproofing situation, the PO has sprayed something gray all over the inside of the cab and roof its not very thick but assume to help with noise is this going to cause a problem with putting some dynamatt or similar product down?