So my brother figured out what the story was with these two cars. They were used to film a video of them driving (drifting really) up Loveland Pass in the snow.
http://media.mclarenautomotive.com/release/191/
http://www.youtube.com/watch?v=8ii3doTMe88
I e-mailed McLaren Automotive and they confirmed for me that those two cars were indeed used in the video.