Lego Snowmobile 6570
Lego Arctic Snowmobile 6570, and Lego Arctic Sleigh 6576.
Both unreleased sets designed in 1999 for the 2000 Arctic Series.
I took the pleasure of collecting the required bricks, creating custom stickers that would have come with the sets, and created the sets myself. Considering I own every other Lego set form the Arctic series, including the value back combo, it only seemed worth it to build the Unreleased sets as well.
(I have scoured the web, and have found no other pictures of these, so I could be the first XD )
(other username is Snowmonk just if you find the others....)