We already do something like that: we allow around 1 million cars on the island (with around 6 million people living here). We auction off the rights to operate one of these 1 million cars for ten years at a time (you still need to buy your own car, of course).
Your proposal would be equivalent to dropping that number from 1 million to 0 million.
I think a reduction in the total number of cars is worth debating, but I don't think 0 is the optimal number.
Though I do wish Singapore would take inspiration from Japan, and eliminate street parking; and in general have the government exit the car storage business.