After hours of pulling the old matting off, it's still covered with adhesive. Should I sand it before putting the new one on or is their something I can soak on it to remove the adhesive?

3m makes adehesive remover that works well and Is fairly safe to use. But I would think on such a big area enamel rudducer or Laquer thinner would be In order using the old wipe on wipe of method. One wet with solvent the other dry for pick-up.

Thanks, that's kind of the direction I was going. Just didn't know if they made something specially for fiberglass.