Strange overspray?

[irvsmith]

On my DD XC90 I noticed the back trunk lift had some form of an overspray. I think it is strange in that it is localized to such a small area with limited impact on the door or bumper. I have tried washing, hand polishing with Meguiar's UP, 10% IPA. Given that this SUV has been taken to the beach and pool a lot I am wondering if some sunscreen sprayed when packing a beach bag. This would explain why it is limited to just that section of the door and bumper.

If it was sunscreen I would have thought washing or IPA would have done the trick. Am I going to have to bring out the GG 6"? The door needs it anyway but wanted to know what I am up against if possible.

Thanks in advance.