Quite a lot of people use the foam too thick where you want it to move. Mates have used mine and its so thick it just sits there. You want to make sure that it does move and is diluted as such. I tend to spray it thick and then my second time round the car adjust to make it a little more watery so it moves the foam. Idea being that it runs down the car and takes the loose dirt off. Again, its not a substitute for using a mitt and buckets, its just helps make that easier and helps prevent swirls and light scratching.

Not sure what Snow Foam you used Gleen, but in all my time of using it its never turned any bumpers or rubbers to go shitty.