yes all post 89 cars run on unleaded. Infact... all minis will run on unleaded. There is so much crap kicking about in a 80K+ engine itll keep running for the normal length of the engine and by that time your gonna replace it with a post 89 anyway cause the box will start to go first. (listen for a low whine at low speeds).
Just the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown.