We use Meguiars Hyper Wash; it's incredibly gentle yet cleans well, offers great value for money (costs £22.53 for 3.78L, but the dilution ratio is a staggering 400 parts water to 1 part product) and does not need to be used with anything else to generate thick clingy foam. More information about the use of foam, plus example images of Hyper Wash performance, can be viewed on this link...
http://www.polishedbliss.co.uk/acata...e-faq.html#1.2
