I looked at the label on my current car soap :
According to the description it is supposed to wash off clean with no additives, etc. Also, the name in itself seems to indicate that it's a no additives/no frills coating.
I'm trying to salvage this soap since I have a brand new gallon - want to be sure the soap is the problem before I buy a gallon of something else.
Obviously I will try to revive the coating with Reset and see if that brings back good water behavior. If it does, I may do some spot testing and only wash one side of the vehicle with this CG soap and see if it changes the characteristics...