There is very little prep work involved when using Dupli-Color's truck bedliner spray paint. If there's any rust to be repaired, this is the time to do it. Other than that, use a putty knife to scrape off any excess "gunk," and remove all debris from the trunk. Now is also the time to repair any body sealant that has detached itself as pictured above. We used some 3M body seam sealer applied with a caulking gun.