Not sure exactly what that is, but I thank you for the pics it still helps. Since you said it's not on the paint but more likely etched in to it I suspect it's bird droppings or possibly sap that ate away at the finish. You can use a clay bar at first just to make sure the area is clean but it won't likely "fix" the marks. Next use a light polish to remove the marks, swirls, oxidation, etc. in the clear coat. The Meguiar's Ultra Finishing Polish M205
is one of my favorite light polishes. If that doesn't work step up to the Meguiar's Ultra-Cut Compound M105
which is an outstanding polish that should definitely take care of it. If you are just doing those spots you'll be fine working it in by hand with good arm pressure. If you want to do the whole car and bring it back to like new condition pick up a safe and easy to use buffer like the PC 7424 XP. Check out this kit if interested as well - DI Packages PC 7424XP with M105, M205 and 5.5" pads
. Let me know if you have any other questions and I'll be happy to help.
Greg @ DI