303 will not remove defects. Mothers and Megs will. I know 303 recommends Aerospace protectant for head lights, tail lights, and clear plastic but I prefer Megs Plastx for defect removal and Plexus for regular cleaning.
I got thrown for a loop when i read the first two posts.. I did some looking on the 303 website and it turns out that you can apply the protectant onto clear plastics and windshields! I'm dumbfounded that i never knew of this application!