Another possibility is that he had a nervous breakdown or substance abuse episode, leading to both the paranoid emails and the irrational vehicle operations. Obviously I'm not saying that's the case, but the extremely irrational driving goes fits a theory of paranoid delusions (brought on by any number of mechanisms), just as the hacked car system goes with about to uncover something big.
Yeah, we really don't know. But I'm extremely uncomfortable by the fact that foul play is a real possibility. We already know that the federal government is operating largely in secret and without regard to the law (their insistence that are indeed following their own secret set of laws doesn't provide me much solace). We already know that various press organizations have been wiretapped. I feel like I've woken up in…
Maybe in 10 years some whistleblower will come out and admit, but probably not. The way Snowden is being treated you'd have to be crazy to do it now...