Rear Ending (short version)

Watched a guy drive for about 5 miles with his left signal on, swerving over the yellow median line multiple times. Stopped short, again drifting to the left - probably playing with a phone while driving.

Ends up rear ending a Camaro. No real damage; neither of them stopped. Both had plates tossed in the back window; my guess is they were together transporting cars somewhere.