This happens to me also. At the car wash I use they have a liquid dash treatment. I asked them to use that on the window trim moldings. It has been effective. I am 74, have some heart issues, and will continue to use an automatic car wash. Replacing the moldings with new moldings that will continue to discolor is not a solution for me.
How was it washed? They went through a local touchless car wash under the impression touchless being safer for the paint, not realizing the aluminum trim would become oxidized effectively. They will be hand washing it going forward I believe.