Car Dock solution
I have a thread over in the Maxx forum showing how I mounted my phone using the Griffin dock for the Ultra/Maxx, using an AMPS mount. It was not as easy as past phones because Griffin did not use the 17mm ball that everyone else does. Anyway, here is the link. [Only registered and activated users can see links. Click Here To Register...]
Just scroll till you see the pics for the final result. I'm assuming this works for the Moto X and Droid Mini docks as well since they are also made by Griffin.