Wish I had pics... They are white cube vans with what looks to be an aluminum trim that runs the lower half. There is a grey streaking that has, I think, penetrated the fiberglass. Not anything that is on the surface?
I have tried some test areas with various cleaners, bleach, and heavy scrubbing. The customer is not real keen about acids, and I am not familiar enough to try yet. It is a new customer and we are trying to fix the last guys neglected areas.
Thanks for any info... Josh