Mitsu & Lotus are in total disarray, so cross them off. Also, one can argue the 3000 was never a true sportscar as it weighed 4000 pounds and shared its platform with a sedan.
The Nissan, using your logic, that means there was no successor to the 240z, or 280z; surely you must know that after the '96 model year the car had a successor not 7 years later.
MR-2 had the MR-S about 5 years after it went out of production. And nevermind that Toyota more than made up for not making a successor to the mid-engined mediocrity with the introduction of LFA. Which, one could also argue that by doing so also acts as a replacement for the Supra (which happened to also have been built off a sedan platform, although it weighed several hundreds pounds less than the Mitsu, but was still a porker).
The RX-7 was last seen as a '95 here in the states (although it ran through '02 in its home market). And thanks to majority ownership by Ford we were given a 4-seater, not-quite-the-pure-sportscar-as-the-7, but still powered by a rotary.
To maybe restate myself -- is there another company with the capital of Honda that initially made a hell of a car/statement, rested on its laurels for a decade and a half, then waited another 10 years to bring another to market? I don't think so.