Best Car Wash Foam Gun is very nice product. Includes everything to adapt the fitting to your common hose. The little boat has marks for the right measurements. Fill it with self-sparkling soap until indicated, then with water.
It generates enough foam and is perfect for giving a layer of soap to your car before passing the chenille glove to avoid scratching it.
Even if your car is not too dirty, and you are only giving it a maintenance wash, you can foam it and then remove it with glove and water, without extra soap.
