Use baking soda ,, it will come off with that any place on your car and then wax it or polishing will help as well but mix it with light water till you have a little more than a past ,, we use that on all cars that come in with acid rain problems,, insurance companies don't like all over paint jobs on a new car so that works great
I don't know about br kprs frnd. I would use 0000 fine steel wool. It might take a little time but you will have a good result. Then finish up with Rain- X.
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