I just uploaded a video to my YouTube today that may answer this question perfectly! I ended going went with the Foam Cannon HP kit (with Karcher adapter) and bought a Karcher K2.360 Electric Power Washer from Walmart for $129 a few weeks ago, but didn't get a chance to video it until yesterday. Here is the quick HD video of it in action ~
I also went with Mequiars HyperWash for the price (about $25/Gallon), value (how little you use) and effectiveness (LOTS of foam suds). Additionally, this allows you to use less of the Adams Car Wash Shampoo when doing a 2 Bucket low risk hand wash (in conjunction with the pre-wash Foamer & HyperWash for a long dwell time) to then finally top it off with Adams Spray Detail when drying for a quick but amazing result weekly wash.
It's actually quite surprising how little HyperWash you use in the Foam Gun. 3 oz (3 pumps if you have the dispenser) is all that is needed with the rest of the bottle filled with warm water for best effect. I absolutely love how easy, fun and quick it is now to make my daily driver look good every week (especially when using Adams products for EVERYTHING else).