Flat clear coat

Hey guys. So I post process all the parts and I wet sand with a DA. However I still get bumps even though I sand pretty well. Is an in mold coating the only way to get a super super flat surface or should I being a stiff foam sponge and wet sand like that?

should use a hard block to sand as much as possible. Also you should fully post cure your part before painting, then fully post cure your paint after it has finished gassing off, and tacked off