Nick,
I just read this on the Detailer Paradise site about P21S:
Quote: "This bodywork shampoo is a gentle, biodegradable liquid car wash. It is the only automotive car wash based on a unique blend of cosmetic ingredients including wheat germ and sugar-based surfactants. This formula ensures the shampoo doesn’t remove essential oils from you paintwork as it deep cleans the surface. P21S Bodywork Conditioning Shampoo is tough on grime while gentle on your paint. A ½ capful in a large bucket of water is plenty for most cars."
Now I'm sure this P21S is great stuff and will clean your car beautifully but what " essential oils" are in the paint on a car? I didn't know that there were any oils in automobile paint. Enlighten me.