Thats a funny question!
Actually i have a '91 with 264K on it now. Runs great by the way.
Anyway, what i did is kind of ad-hoc. I tok a 2x3, cut off a piece and then screwed that to the floor in getween the two front seats, then i mounted 2 of the smaller "Euro" style cupholders to the top of it.
It works great. you need the height to get the cupholder body above the little "tray" thats under the hand brake in the 91 which has a lip thats about a half-inch high. A 2x3 is almost exactly the right size.
I dont have cupholders in the rear of mine, but it does give me 2 in the front. I found 2 wallboard screws anchor the 2x3 into the carpet well, without making it so long they penetrate the floor. (and its been pretty stable).
The only thing that happens is occasionally one of the plastic cupholders will break, in which case i go to a PepBoys and buy a new one. (its only happened to 1 of them in the last 7 years since i put this mod in though).
this is a picture of the cupholder i used