If you wax cars I can recommend buying a tin of collinite 476s the best stuff out there and a little goes a hell of a long way. Once you have cleaned cars and then applied that all they need is hosing off again. Very good product and cheaper than most out there. Last's ages I would have thought you can do between 50 and 70+ cars with a large tin £26 approx.
Autosmart stuff is OK you can get better elsewhere but on the whole as a one stop shop pretty good. I used to run a couple of hand car wash/valeting businesses so have tried most products out there. Generally comes down to who is using them and getting the right balance of dilution.