Hi All, I went up to Sandy Cape (Jurien, WA) for Easter and on the Easter Thursday it rained leaving the tracks muddy. When I went to clean off the Jayco, the body came up clean as a whistle but the chasis and underbody is caked with mud and won't shift. I took to it with truck wash, high pressure cleaner and a scrubbing brush and still wont shift. It has set like cement. I dont want to scrape it as I dont want to scratch off the Galv. Has anyone any ideas to get it clean?