I don't know, I'm never really keen on the whole "panicked driver hides body" theory. I mean, if the road was truly so quiet to the point that nobody heard any kind of commotion, then why bother hiding the body at all? The driver could easily just drive off and leave the body. In fact, I think the natural panicked instinct of about 80% of people in that scenario WOULD be to just drive away. Why would the driver even implicate themself at all. They would not be criminally at fault if they just reported that a drunken Brian walked in front of their car and it was an accident, but they would be at fault for hiding a body, so that seems to be not only more work but also more chance of legal repercussion. I realize that a hit and run is far worse, but at least with that they are making sure they can't be fingered as any sort of suspect, so that would make more sense to me.