I know i'll be missing something here. I always am.
Washed the car the other week, then applied Megs All Metal Polysh to the tail pipe.
Within a matter of days, it was caked in crud again & looked like it hadn't been touched:
This is it only after a couple of days or so.
Do you get sealants for this & if so are they needed / what do they do exactly?
Or is there no way to stop this getting caked so quick?