I-76 East of Brush, CO. Car runs off road?

Christmas Eve,  (hence the music).    Watch the second car that passes me on the left closely.    It eventually slides or runs off of the road after it passes the truck ahead of me.      At first I thought it was just taking an off ramp 'aggressively', but saw the car in an open field, far ahead of the ramp, when I passed it.          The car was not there when I passed the same location in the other direction 12 hours later.      Video from a Blueskysea B1W dashcam.