What the heck is "snow foam"? I googled it, got plenty of youtube videos. All the videos show is a car being sprayed, then the video ends. What do you do after spraying the car? Do you then wash it as you normally would, but using the soapy foamed up car instead of a soapy water filled bucket?
To clean a car, you have to hand wash it. Dirt sticks to the paint. Spraying it with a foam isn't going to clean it. It is just going to get the car soapy. You have to wash the dirt off. Paint oxidizes. You have to periodically polish the paint to remove the oxidation leaving clean and smooth paint surface. After the polishing, you have to protect to slow down the oxidation process. You do that by applying a wax or a sealer. You do this more often than polishing.
If you snow foam the car and that's all your suppose to do, later polishing or waxing will scratch the crap out of your paint because the grit stuck in the paint is still there.
Wash, polish, and wax your car properly. Not only will the finish on your car keep the brand new look, but with frequent polishing with a good product (twice a year), after a couple of years, you will slightly change the color of your car and it will be unique. Your paint will look like the shine is miles deep. The color will be ultra rich and glossy. No one else's car of the same make and color will look like yours. Park side by side with one and yours will look like a million bucks and theirs will look ratty.