Car haulers are manufactured with a very thin layer of paint. When you used the green stuff, the chemical became embedded with the paint, meaning that you will now probably have to paint. The finishing on your car hauler does not have a clear coat nor any other coating other than a very cheap paint job. Many older RVs with the sheeting are the same way.
If you continue to try to remove the streaks, you'll soon find out that what you will be removing is the thin layer of paint until you get down to the primer or bare aluminum.