X7 SUV.

AFAIK, I don't think cosmoline is being used these days but some sort of rust proofing agent is in there..
I know this for certainty as when the car was brand new, on the 1st or 2nd wash, I did pull a -wax'ish booger- that had somewhat plugging out of one weep hole.

But whatever staining it is leaving, or reoccurring consistently after -polish cleanup-, has driven me to post the ask I suppose
It's a continual chasing after the weep hole syndrome...

If this wiped off easily with cleaners/mf, I suppose I wouldn't be be posting the inquiry.
BRB. Let me pull out the big guns and do a terminator wipe