Cement On Porsche Need Professional Help

[kabel]

The vinegar should not hurt the paint, it is a common solution for helping to remove water spots too. Try to re-hydrate the spots if you can by leaving a wet wash cloth on them for a while.

I do not think it was actually concrete, one of the under layers of a road is this very fine grit, grayish material that when mixed with water does stick and harden like concrete. Had this happen to me a few months back when the road leading to my house was being redone.

I ended up washing the car multiple times, gently scubing the affected areas, then used a clay bar to remove what remained. If I had a pressure washer I probably would have (cautiously) employed that too.

You will want to apply your favorite wax product when your done though.