I'm going to undercoat my fenderwells, soon. I put it on my "things to do, this winter list". I still have a week or two before spring starts.

I stopped by the parts store to see what was available. They had 5 or 6 different brands or types.
Question, what should I use to undercoat my fiberglass Cobra fenderwells? Brand? Type? Pro/Cons
Thanks
Dwight