When I had my Formula Z (about 6 years ago) I bought some of those metal strips that sit on the rolled edge of the running board and riveted on. They had raised holes punched through them which really helped keep the boots on the boards, but weren't so sharp that you would rip your pants if you brushed up against them. Worked awesome for my big boots (size 13+) since they always sat on the rolled edge whenever I stood up. As far as I can remember, they were a Ski-doo part, came in a few different colors and sold for about $35 a pair.