I have noticed the reddish specs and attribute that to tar and tire crap... wax takes it off pretty easy... but yeah, around the exhaust tips it gets dark if i don't wash it for a couple weeks. I drive it pretty hard too... and washing it usually takes it off... but after i used 409, it showed me how dark the bumper really was around the tips. But then again the Borla hasn't been on there long, and the darkness is getting less noticeable... might have been the new muffler burning out.