Got collision working. Just need to improve the movement so it’s locked to the x and y planes and so you can jump. Currently your cube can easily topple over and then your steering will veer you off in crazy directions.
In unrelated news, I’ve been listening to lots of this: http://www.youtube.com/watch?v=ABYnqp-bxvg while I work. It’s a great feel good song and also has a brilliant video!