Clay Bar still the best thing for dirty paint? For three years of leased ownership on my Sierra pick up I have only washed it.
I bought the truck at the end of lease, and tried some of
this from Mother's
It worked ok, but not great. I only did 1/3 of the hood before stopping, and thinking that maybe clay would be best. The surface prep stuff did remove a lot of dirt, but not all. Maybe I was just expecting too much, as the truck has sat outside in the SC sun for three years