[Jack Hammer]

“If Marty McFly and Doc Brown were ever to reunite for a sequel to Back to the Future III, the old time traveling DeLorean would need an upgrade of some sort...”

It certainly would, since it was annihilated by a railroad train at the end of Back to the Future III.

[freepertoo]

I love this series and III was my favorite of the trilogy.

[whd23]

The DeLorean was indeed destroyed at the end of BTTFIII, but continuity could be preserved by having Doc Brown use his train to go to a time when the DeLorean was stored in the cave. All that's required is that the DeLorean be returned to the cave before Doc and Marty go to retrieve it in the '50s.

Fun movies