Wax free soap?
 

I just bought a new truck that has a flat black paint. The previous owner told me that by using soaps with wax in them it slowly made the paint glossier every time. Im wondering if anyone knows of a good wax free car soap, because most of the soaps on the market contain some form of wax. I heard the cheaper the soap then the more likely it is to not contain wax. Thanks for the help