@alvis
I won't argue about the MR2 similarities, as well as with the Pontiac Fiero. Any more details on the car? When was it produced? I gather from your description that it was a sole prototype, and made before the Stratos. Probably Lancia decided that it hadn't enough of a market to justify building a mid-engined sports car, and so concentrated in making the Stratos as an all-out racing machine.
I have to say though, using my very limited knowledge of aerodynamics, this car could have been a bit of a handful at high speed (rear axle aerodynamic lift), with the flat back. Hence the (eventual) Stratos' short tail and integral spoiler. I don't have any references though, so don't quote me!
The profile (in part) also reminds me of the old Lotus Europa. Especially the buttresses at the sides of the rear screen. It would be interesting to have one of these cars made today as replicas, using modern suspension, brakes, electronics, engines, etc. Sure it isn't original, but it's different, and surely worth watching, because they are beautiful cars!