If these are your personal cars and trucks I wouldn't use anything stronger then what your already useing.By hand washing it will clean your paint without doing any damage to your wax job.If your layering wax on top of wax the auto store soap is what you need,anything stronger will remove a little wax on each wash.When trying a new wax use dawn to strip off all the old wax before you start,never use dawn unless your wanting to strip the wax off.

When In Doubt Think It Out