its all about the lubrication, i use AG shampoo and conditioner with a dash of snow foam in the bucket, all the cars we do are first rinsed and then snow foamed and then rinsed again and then foamed again to help in the lubrication. CG maxi suds is good stuff though well worth a look warren. most shampoo's which are well know will do for the car as long as they dont have any traces of sodium and are PH neutral you should be ok.