I think your problem might lie in around the snowfoaming Paddy. I would always snowfoam with a 5-10 min dwell, then pressure wash to rinse without putting any lambswool mitt near the paint. You can use the dwell time to start working on agitating the wheels which would've been the first thing I hit, with some wheel cleaner (I use a combination of Orchards de-tar and 50Cal retaliate wheel cleaner).