Ok, so I had a really insane idea when I was playing around with magnetic suspension last year at our pinewood derby. I got irked at the people who made pinpoint cars and thoroughly beat my own, so I tied to combine the two, using mag-lev suspension on a pinpoint wheel design. I tinkered with the idea for a bit, then realized that there was a better way. What if I used magnets to float the wheel? Cut the entire inside of the wheel out then line the inside of the rim with neodymium magnets. Get a much smaller wheel or disc and line the outside of that with magnets, then place it on the outside of the axle. If the magnets are all aligned so that they repel, the wheel should float around the axle. Now, that basic design is unstable. It would literally fly apart the moment it is let go. So, I thought that gluing a ring magnet on both sides of the wheel and attaching two more ring magnets to the car body so they repel the ones attached to the wheel.
I know that's a bit confusing, but I'm building a 3D image in Blender that should help. Now, here's the question: would this work? I'm concerned the whole business would just fly apart halfway down the track. I think that if this works, it would be almost frictionless, with only a tiny bit from the track and the air.