i used a magice eraser on my crown vic today after i washed it helped take off a lot of paint scuffs road crap and such as well as all the windows(i have a well and hard water) then just hit the car with a lite waxing cant see at all where i magic erased at but with out wax it does show
wouldnt dare touch the gp with on except the windows the cv is silvver so it doesnt show flaws as bad

theres also some acid stuffyou can use But id never use it