Strange stains on paint
Hey guys, newbie here. So when I first got my mustang I didn't know anything about detailing, all I did was wash her occasionally. After two years of no wax or paint protection, I finally wised up and taught myself how to polish and wax my car. The bad part of this is that now I have something stuck on my paint right behind my right rear wheel that won't come off. I have tried meguiars polish and claying the area, but nothing has worked. It looks almost like dirt that eventually worked its way into the paint. Is this permanent or would a stronger compound polish to make this go away?
2003 Sonic Blue GT -- SR Performance CAI, BBK 78mm Throttle intake, Magnaflow axleback exhaust, Bama tuned