LogFAQs > #950641523

I can only see this getting the negatives of a 3 wheel car, without any real benefit outside of being less hindered by a flat.

With a three wheel car, a wheel is in the center, so you're going to hit that pothole/bump. You also have less weight and in some cases it's not fully classified as a car, so you only need a motorcycle license or pay less tax/etc.
With 5 you'd have slightly better weight distribution, but that's about it. Also this is going to cause more confusion with the already existing fifth wheel.

The drivetrain layout also hurts to think about.