Awesome project. I have a spare set of 360 wheel pedals so I've been intending to do something like this (with a cheap goodwill wheel to pair with the pedals I already have).

What I really like about your project is that you used the whole radio which means you get the programmability out of it. My thought was to use an arduino to get position info and then output a ppm signal that any module could plug into. Plug in a spektrum module, kyosho asf module for mini-z, am module for losi micros etc. What I lose, though, is anything like dual rates/trims/expos etc unless I program them in manually.

Can't wait to get your impressions from running outside or on a track. My feeling is that it won't be competitive for the same reason video gamers use thumbsticks, it's faster turning lock to lock which is very important at RC racing speeds.

Have you thought about how you'll setup wherever you end up running it? Lawn chair and wheel in lap? Something fancier? :P