I cleaned up the inside fender and applied the 3m rubberized coating like I have in the wheel well area. I was thinking about spraying just can clear coat, as I don't have spray tools, over that so it would make clean up earier in the future and have a nice semi gloss to it. Mainly though, it's for the ability to windex the surface when I get any dirt in there.

Any thoughts on there being any breathing issues under the clear for the rubberized? I assume there isn't an issue in covering the #M as long as it is good and dry/cured

 

Before you attempt doing it, just try it on a sample piece first. The chemicals in the clear may attack the rubber and possibly bubble. Just a thought...

 

And the clear will not be flexable like the rubber and could crack when the rubber is flexed.

 

3m undercoat is paintable and it says so on the can, I would do a test sample to be sure. More then likely you will be OK.
Lynn