It will remove any protection built up on the paint, including wax, thats why cleansing the paint work is so good at allowing the wax to bond. One of the nice things i like about Zymol products (accept for clay and cleanser obviously) there designed not to remove the wax you put on last time.
I've tried this by cleaning half my bonenct using normal car shampoo, sponge and shammey, against there own sponge, soap and shamey. I then applied water and it was still beeding off the side cleaned with there stuff.
Not that effects these thread, but one of the reasons i settled mainly on using it I think we may be seeing some shiney cars soon lol
Andy
Dave/ Andy cut and past your comments well worth stickying imo