I'll be honest, as much as I loved my pressure washer (Subaru 3100PSI model), I probably loved my Spotless DI system even more. Washing my car at home (when I was in a home) was fantastic. I could spend more time washing the car and less time drying it. Not having to deal with the sun drying the hard water was great. Griot's Garage makes a similar tool. I have the Spotless system below. The 2nd video is a good video that I found that shows results. It's even narrated in a British accent, in case you like nature videos.
And below are my pre/post results.