Here's my Brushless ArtAttack from two winters ago. 4S Lipo, Quark 125b, Feigao 9L ribbed can. I didn't wnat to spend the $100 or whatever for the electric motor mount so I made my own which worked better than I expected.
Vid 1 (still playing with cells/gearing)
http://www.youtube.com/watch?v=875HUnSZAdI
Vid 2 (Good performance, but conditions had to be right. Too deep or too slushy and it would pack the inner part of the track with snow and clog)
http://www.youtube.com/watch?v=g1yLWctmOmc