I haven't used the Sonax Gloss Shampoo, but I love Adam's Car Wash. It suds up really well and smells like cherries! =] I heard Lusso was really good too, but I haven't had a chance to try it yet.
I would go with Adam's between those two. Now on the other hand Lusso is a whole other story. It's a wicked shampoo but is prob not something you would want to put into a foam gun or foam cannon due to price. It's lubricity is off the charts and really IMO no other shampoo is even close to it.