Road rage is a motive that's been brought up since Dan was murdered. I've dismissed from the beginning for the following reasons.
At no point during the conversation did Dan tell the other person on the phone that somebody was harassing him on the street. If there was a road rage incident, the person in the Prius would've tried to get Dan's attention right away, and I'm sure Dan would've mentioned something during his phone call. But he didn't.
To further back that up, when I read Dan's words, "Somebody's in my driveway." That sounds to me like it's said with an expression of surprise. This furthers the idea that at no time did the Prius driver--if it was a road rage incident--try to get Dan's attention while they were out on the main streets. Also, Dan made no mention that somebody was following him.
One more thing, only one bullet was fired at Dan. If this was a "rage" incident, my impression is there would've been several shots. I mean, if the Prius driver is going to follow Dan the whole way home, wouldn't the driver then make FOR SURE that Dan was dead? If any of you have any doubt about this, look up "Timothy Davison" on here. Now THAT was a true road rage incident--multiple shots into his vehicle. That case is still unsolved by the way.
Plus, now that we know more about the Prius, we know that it had a SunPass sticker on it. There's no reason to have one of those in the Tallahassee area--there are no toll roads there. I don't know--maybe it's just me--but it seems to me that locals would be more likely to suffer from road rage than outsiders. I admit that's kind of just an instinctual thing but I believe it's in line with common sense.
I'd also add that the percentage of people cruising around with guns in their cards is very low. So, not only do we have a person prone to road rage, but who also has a gun in his car with the capacity to kill someone . . . while driving a Prius, that's certainly a unique demographic.