I'm glad you mentioned this!
Here's an interesting(?) oddball item - I think 303 reacts negatively with the factory headlight film.
Before I completely removed the factory coating using the 3M method, I accidentally got some 303 overspray on my headlights while treating my cladding. It left what looked like water spots and smears on the headlights and I wondered if it was permanent because I couldn't remove it with Windex or a regular wash.
Then I saw "Do not use on clear plastic" in the 303 directions. YIKES!
However, I also noticed that there has NEVER been any similar negative reaction on my big shiny perfect-looking rear taillights or any other lenses.
Hmmmmm, what is the difference?
After reading this tonight, I figured "what the heck, I'll play guinea pig"; I'll use the 3M stuff again if I need to. I intentionally sprayed some 303 on the headlights just to see what would happen and it was 100%, completely fine!
So... I wonder if 303 just doesn't like headlight coating films so I'd recommend being careful and testing 303 on "perfect", factory headlights.
![]()