I don't know, I'm still inclined to think that the Nissan is just a random driver. Many people take drives late at night for a lot of reasons - to clear their heads, to help their infants go to sleep, ect. As you pointed out, it could have been someone passing through just checking their GPS. Nancy Grace brought up a good point that the dual exhaust is not a factory feature on Nissan Altima. If it is a local, then the car should be recognizable to someone. Hopefully?