Originally Posted by Michael J Fox is Canadian
One important thing which has been brought up is the family connection; the McFly's did not move to hill Valley until the 19th century (remember William is the first born in America). As well the spacial travel. Now doc did say in episode 1 he added a few bells and whistles to the delorean. Aside from the automatic retrieval, we hadn't seen any differences.
Well, there were also the calibration devices that Citizen Brown used and the satellite that Doc used to sync up the calibration units with the paradoxal DeLorean. Although, I suppose he could have always had those. We never got to see Doc tinker with the DeLorean outside of the limitations of the past in the films.