I'm sure an easy bolt on throttle body fuel injected "carb" kit could be made to fit on the stock intake manifold with minimum hassle. All you would need would be a timing input, water temp input, air flow input, and throttle postion input.
I owned a 91 Geo Metro once and this car had the simplest one barrel throttle body injection system on it. In the 200K miles I put on this car, I never had a problem with the fuel system or any sensors.
If a big company like Holley was shown enough interest, maybe something could happen.....
