how to remove this from my car's paint?

[Alluck]

seems like oil hardened on the paint?

 

[Art138]

I had a similar issue near the rear upper fender. I used 2000 grit sandpaper soaked in soapy water. Subsequently applied an orbital polisher to raise the shine. Key is to keep the area moistened with soapy water as you rub with the sandpaper.

 

[Zacster]

Did you try detailing clay? I wouldn't use sandpaper.

 

[joebruin77]

seems like oil hardened on the paint?

It's hard to tell from the pic what exactly it is. Is it possible that it is tree sap? If so, a professional detailer shared his secret to get rid of tree sap. Get some alcohol-based hand sanitizer. Apply a very liberal amount of the hand sanitizer all over the tree sap. Be sure to apply when the paint is cool and in the shade. Then let it dwell for 1-2 minutes before gently rubbing it off with a clean, soft microfiber. You may need to repeat this 2-3 times if the sap is really hard.