Nothing worse than washing 220M's after a couple of months (which is where I'm at). SONAX + power washer + Daytona wheel brush is tolerable. But I'm with the OP, love having a squeaky clean car, hate washing it though.
Current: E92 M3 Sparkling Graphite/Bamboo Beige/6MT. E36 M3 Techno Violet/Dove/5MT. E85 Z4MR Alpine White/Imola Red/6MT