I'm not sure where it came from, but Re-Volt is floating around in the interwebs. I just thought I'd post that the file structure is identical to that of the PC version. I haven't tried modding it at all, I just wanted to pass it on that it's likely that the addon cars & tracks will work. In fact, other than the executable it looks 100% identical to my PC version structure-wise.
Here's a resource of cars/tracks to pull from: