The big gaming project I've been working on recently has been cleaning up my vehicle rules for DCC/MCC. This is the first thing I've tried to sell or publish, so it's pretty new ground for me (up til now, my players have been the only victims of these whims).
I originally started to develop this as part of our ongoing DCC game. The group jumped through a magic portal and ended up on a post-apocalyptic wasteworld. They came to believe that there was a way to escape this hellish world, but the path lied across a desert wasteland. To reach this promised land, they stole some cars from the local waste gang (The Disciples of the Wheel). Of course, a Mad Max style chase ensued. In the years since, I've been slowly refining those rules, playtesting with local groups.
A big part of the rules is the Vehicle Record- your car's character sheet. One of my goals was to keep the rules simple enough that they felt like they "fit" within DCC. So very basic stats and tables to resolve results.
Outside of formatting, the rules are done. Once cleaned up, I'll be submitting to Goodman Games to get licensed for third party publishing. In March, I'll be running a "Disciples of the Wheel" tournament at GaryCon- I hope to have a stack of printed copies to bring with me. Up until then, I'll be sharing bits of the rules & explaining my thought process here.