This link will show ATV converted to snow machine.
http://www.a2xtreme.com/2000/paxhtm/snowtrax.htm
This link will show 4X4 converted to snow machine
http://americantracktruck.com/
I believe the GMC Savana used on the Mt Washington auto road use this conversion in the winter.
Three years ago, I remember an altercation between the Pittsburgh snowmobile club members and a group of snotrax users. I didn't stick around for the conclusion but the club does not want snotrax users on the trails. Maybe someone can clue me in on this.