I would guess Chili (maybe from Wendy's) out the window at about 60MPH after a night of drinking.

You were trying hard to stop, but you were on the highway, and couldn't get over in time.

Leslie has done this twice in two years, both times on Christmas Eve. Once on my Xterra, once on her WRX. Washing it off at 3AM at the car wash is a very cold experience.