Roll Bar install help

[Ray Sta.Juana]

I just got my rollbar from Autopower and plan on installing it right before
the OCT track day and I need some suggestions.  My question is, what should
I use to cover the bolts that would be exposed on the underside of the car
and in the wheelwell?  I once saw an install that looked like the bolts were
covered in some type of rubbery coating. Any idea what that might have been?
Any better ones than that? Also, I want to put the rollbar in without
cutting the carpet, ie. just drill the holes directly on the carpet. Good
idea? Bad idea? TIA

Ray S
98 Sentra SE w/mods