Nissan doesn't have a supercar like Honda's NSX or Toyota's LFA. What they have instead is something that can beat most supercars, the GT-R. That's nice, but imagine if these two MID4 prototypes would have made it into production.
A crazy mid-engined Infiniti would probably emerge from somewhere. Of course back in the mid-eighties, there was no Infiniti to start with. That only came in 1989. But Nissan wanted to develop new technologies, and what's better for a testbed than a futuristic supercar?