bcgreen- Ah, thanks for explaining, that wouldn`t have occurred to me as I have spraybottles of shampoo mix that I keep with the rinse/wash buckets for Wheels/etc., all mixed up with more than enough for every wash`s wheels/wells/undercarriage. Maybe makes more sense for me since I use the same mix as a concentrate for the foamguns.
EDIT: Now I`m wondering whether people use the same shampoo/rinse buckets for wheels that they do for the rest of the vehicle. I`d worry about getting the shampoo buckets contaminated; I go *MANY* washes without replacing those since for me they`re basically just a repository for the wash media but I`m guessing that most here redo them at every wash.