Hi everyone !
There was always two things in bttf2 the bothered me.
One is Biff and Delorean and second is Doc become some way commended by goverment (newspaper )
When Marty and Doc travel to the future, senior Biff spot the Delorean and instead of saying some trivial "WTF is this?" He KNEW that this was a Time machine, and knew how to set a clock, go 80 miles etc... Ha ! He even told his younger self that in the future Marty or Doc will go after him.
Question remains : How he knew this much about Delorean?! How he knew this "crazy, wild-eyed old man who claims to be a scientist" ?
In the 2rd part Doc shown Marty newspaper with text "Emmett Brown commended". I assume that in later years he told the world about time travels (and create a Institute of Future Technology <-- non canonical). Then we got two options:
1. Doc in second part (future) is still anonymous, he become recognizable after they alter Biff Hell Valley . In the end of third part when Marty asked Doc about the future Doc replied "we already been there" .
In this timeline (in the future) Biff dont know anything about time travels yet. Doc can build as many time machines as he want because in the future he is... First Citizen Brown (Eeevil Ending ;P )
2. Doc in second part (future) before he come back for Marty he learned that he was honored, he become recognizable person. This would explain that Biff knew what is "Delorean" . But in this time version we don't know how long Doc remained in the future ("Oh no ! Marty's son and his family are in trouble ! I must come back.. but before. Let pimp our Delorean with flying ambility and 18" rims .Yeaach") and.. How may things he know about .. THE FUTURE !!! ;)
There always bother me what "the status" (dead, live,famous, anonymous ect.) have Doc in 2015. For 100% Emmett that goes to the future in the end of first part search for future himself. What he learned? ;) Maybe in game it will be explained...
Sorry if i made any grammar mistakes. English is not my native language :(