Sorry Grigg,
I use to have an old Lincoln with a vinyl top that I used Armor All on. The product would, over time, break down and leave streaks on the windows. I would not be suprised if it broke down with the soaps you have used and left only part of the product on the frame. Have you considered TSP, Tri Sodium Phosphate? I am not sure how the base paint would react but it should be okay, I have used TSP on engine blocks and the like with no ill effect. Just a thought.
