Underwear? What's that?

I think you're right. It was likely Brian himself driving the car that hit him. If it wasn't, I think they would have come up with a distracted driver joke to set it up. Also, the car was really racing around the corner, implying that it was in the middle of an action chase typical of the "Road To" episodes. I would…

"Siri, can I kiss you?"

It doesn't matter! I don't have them anymore!

You're my favorite quote.