Here's something you never want to see.
The wrong-way vehicle appears at about 0:17 in this video, right near the Colfax Avenue exit. Sure, it's not that dramatic of a video, but it's spooky to see. We'll update as we get more information.
Meanwhile, maybe this YouTube comment from Doogie H is a clue: "That was me. Sorry. Just smoked a blunt and Casa Bonita was closing."