After removing the carpet I noticed a rubber type seal or something near the front of the inside. It is under the dash and extends from the clutch all the way to the passenger side door. Its sort of like a sub-carpet. I should remove it, but is it nessacary to put it back in when I put in new carpet?

Anyone?
I really want to know if I shoud just throw it away or if I should keep it.

I think I am pretty sure I know what are you are talking about. The stuff that runs from the seam of the floor board and the firewall, and back up the firewall. Its sound deadener, jute padding with a plasic backing. If its still good go ahead and leave it there. Keeps a lot of the engine noise out. Its removed from the pic because the stuff in mine was water soaked and full of mold. Smelled so bad.

If the material is damaged I think you can buy some kind of aftermarket version of the material from Summit Racing.

If your getting NEW carpet...it should have new jute padding....mine did.

It will have new jute padding but its not going to have what this guy is talking about. He is talking about the padding that is up on the firewall.