Many have reporting finding residue on their windshields after rain. This type of report has become very common since chemtrails have become widespread throughout the 2000's. It should be expected now that we are finding enormous amounts of aluminum and other toxic metals in rainwater.
These photos from Santa Clarita, California shows rain residue. The source says there are no trees or other known causes nearby.
Russ Tanner, Founder, Administrator, Programmer GlobalSkywatch.com My Chemtrail Story