All my amp wires and nitrous lines are going beside that rubber boot in the fire wall. I dont really want to drill and holes in the fire wall so what if I just covers the hole with spray foam insulation? I know it would be ungly but it is in the corner and i would rather have hidden ugly than rusty floor boards? Any other ideas would be great.
Alex

 

I saw an old Jeep one time that was held together by spray foam. Seriously, if there used to be a hole it got filled with spray foam.

Could you use some silicone? I think that would be more weather proof than the spray foam.

 

they have some sticky tacky gum like stuff almost like tar that i used. it worked for me. does not get hard . i got it at circuit city they use it in there shop when going through fire walls. they dont sell it though.

 

thanks