Started cleaning up the cowl last night. Got all the spray adhesive off, sanded it, and cut out the rot. Now I'm gonna clean up the sections I cut out, patch where needed and glue them back in with 3M's 8116 Panel Bonding Adhesive. I'm going the glue route here because esthetics is not critical, and I'm going to seam seal inside the cowl before I put the panels back on while I can get everywhere pretty easily. I don't want to melt the new seam sealer by welding around it. 8116 is used to glue full panels on like quarters, so I figure it'll be more than sufficiant for my needs. The stuff works awesome, I patched a crack in an aluminum oil pan on a VW Passat I had with it...about 20,000 miles ago and it's still holding strong with no issues. I know, because I sold it to my next door neighbor.