I took my 2017 Mercedes Benz CLA250 to the car wash and when he was done he showed me these white spots on my car. For the life of me I did not know what they were. Then I realized it could possibly be the ashes embedded into my paint from my neighbors shed that caught on fire a few days earlier. Now I have this grainy substance on my black paint and car windows. How can I fix this issue myself? What are the proper steps because I also want to make sure it is shiny afterwards without damaging the paint or windows. Thanks in advance for any advice you may have!