That is 1 of the points why Disney (plus the storyline amongst others) didn't want to be the producer or whatever, but when the film was realeased they kicked themselves.
Somewhere on the DVD it mentions that the problem with Future films is getting things right, so they have to just use their imagination.
You got to remember things like Blade Runner as well, this is set in 2019. Running Man in 2025, Demolition Man in 2032, Total Recall in 2084, plus loaRAB of others.
There is probably things in these films that yet haven't been planned, such as the Neon Lights Umbrella in Blade Runner, them Laser Rifles used in Demolition Man etc.
I do prefer BTTF2 over the rest, again I was a kid when I saw it and always believed the future would be like that.
I would deffo buy an Hover-Board, but the PitBull version