Just so nobody thinks I'm just goofing off enjoying the great spring weather we're having here in the PNW:
After sanding that side, I cleaned it off with a rag dampened with odorless mineral spirits and shot some rattle can (that's car-guy speak for an aerosol can of spray paint) primer over the front fender. I had gone through the primer in several spots and couldn't quite tell where I was at. I'll build this up with another coat or two before lightly sanding it again.
More sanding excitement coming soon. . .