Some sort of stain in paint!?

I noticed some dirt/tar black looking stuff near my front wheel today along the rocker, wiped it off and it came off quite easily. However it left this nasty stain in the paint :( :(

I've tried detail spray, tar remover and a light compound and nothing. You can't feel it by touching, literally just like whatever it was stained that spot darker, at first I was pissed thinking it was some bad touch up job for a dealer I never noticed, but can confirm that it wasn't there Friday after washing the car so it definitely took place this weekend.

Thoughts? What it could have been? What I can do or try? Or worse think I'm just SOL :(

https://m.imgur.com/gallery/f8YmM

Use link for pic I suck st this Imgur thing.

Try some WD40

I have had bug juice soaked into the clear before leaving a brown ish stain on my GB.
It would disappear after a couple of days in the sun.

ewitz said:

Try some WD40

Click to expand...

Tried, no dice :(