This is glue. Stong stuff

Here is the tunnel after priming.  Note you can see the rivnut poking through that holds the clutch hose

 

 

Here is the insulation back in. Since the tunnel is wider I wanted a little more space for the gas pedal.  I removed the insulation and used the titular spray glue to stick the carpet to the tunnel

Here is the gas pedal fully depressed still showing clearance.