I have resinous substance on the bumper. I noticed it recently but it seems to have caked/baked on the bumper in the summer heat. I tried to use quick detailer, rubbing alcohol, even tried to use nanoskin but it won't budge. I was tempted to use GooGone but wasn't too sure if it will harm the paint. I have not tried any APC (have Super Clean) for the same reason.

Appreciate any ideas.
Thanks in advance.

Appreciate any ideas.
Thanks in advance.