DISCLAIMER: There is no single "Download Link" for this mod. It's a HEAVILY CUSTOMIZED PC project from a die-hard BTTF and GTA fan. It took me months to tweak everything and finally get it working right but I couldn't have done it without the help of some truly great mod makers (credits/links below). Please don't just start modifying your game without researching and backing things up first. You WILL break it.
I made this video mostly to show what can still be done with this amazing game and to give other BTTF fans some information on how to create something similar, though not exact. I'll answer simple questions but I can't train you on how to mod GTA...you'll have to do some research yourself, if you're up to it! It's a hell of a lot more than just installing a skin or two...we're talking hours and hours of editing files. I've only played with it for a few hours now but it was totally worth it.