Gotta be honest, I use whatever 'crap' you can pick up at Wal-Mart, Menards or something similar for a small amount of cash. Still have winter formula in the trucks right now, and I'm real glad of that-- supposed to freeze tonight and tomorrow night (earlier this week it was 85-92 degrees F, um... WHAT
Never have had an issue with washer fluid not washing off, not on the white ram (frequent washes) nor on the Beast, whom originally
wasn't washed too much (because it was feared washing the dirt off would make it 'fall apart'... until I got a hold of it...)
It's weird that you weren't able to wash it off, maybe I ought to look a little closer.
Pretty sure I would have noticed, speaking as one who has every little nick in the paint memorized so I know if there's been a new addition...