Funny you mention that. My friend just told me something I did not notice. Brian may have ran over himself.
DESPICABLE ME MINION: Whaaaaaaat!?
I'm serious. Look up Brian's death scene on YouTube, at least if your not squeamish to do so. The car that hit him looked exactly like Brian's white Prius. If you want further proof, here's a picture of the Prius.
http://imageshack.us/photo/my-images...yguyprius.jpg/ Now let's consider how many times time travel was used in several Family Guy episodes. There may have been another Brian left behind during one of those timelines, so his death may have been a time paradox. And if it did turn out my theory was true, I'm sorry I spoiled the plot for ya. We just have to stay tuned until the next episode.