This looks like a great day for everyone. A closed track and a few inches of snow present a wonderful opportunity to have some fun sliding around the GT-R on the empty circuit. Adding the snowboarder gives another person a chance to enjoy the thrills. (Disclaimer: Don't try this at home.)
According to the YouTube description, these guys initially hooked up the tether for the snowboard as a joke, but it clearly turned out to be a blast. With speeds reaching over 75 miles per hour, the rider enjoyed enjoyed a high-speed tour of the track in a very special way. The guy was definitely smart to wear a helmet, though.