With regular car wash liquid (PB SS&S, NXT, etc), I've been using about 1 oz plus about 2/3 of the container filled with softened water from the kitchen tap. Settings on the foam gun - well, I have it pulled all the way to the left. I like this combo. Have also tried the Eagle One Car Wash in a Bottle and at these settings it produced an exceptional amount of suds, but seemed to also leave more residue on the car.
Got faom samples from AG yesterday and used about 1.25 oz, 2/3 of the container with softened water and foam gun setting in the middle. worked well, but probably should have played with the settings more to get thicker foam.
Earlier I just started a similar thread at AGonline.net for input and feedback.