Gave mine a manual wash, albeit just with shampoo.
Meguiar's Gold Class Wash is pretty great, though for the foam cannon my friend has, it seems like 1:4 works better than 1:9 that most people were recommending online.
And yep, the butt of the car gets dirty, quick. I also need some clay bar next time I am doing a real wash.
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Current:
2019 Chevrolet Camaro 2SS 1LE M6 Shock
GM Performance Intake and that's it, because driver mods before car mods
Past:
2009 Mazda RX-8 GT M6 Velocity Red Mica (Sold)
2015 Chevrolet Corvette Z51 2LT M7 Velocity Yellow Tintcoat (Flood totaled)