Hi Sp ,

I think you can assign the non recognized G27 buttons through the Logitech Profiler. I'm not sure how it works, but I think it's something like this:
In the Logitech profiler, you assign those G 27 buttons to keys on your keyboard, and in the game you map the functions to these keyboard buttons. Then, when you press the buttons on the G27 while in-game, the profiler convert those inputs to the keyboard. Hope it works!

*EDIT*: or look here... http://www.gt-legends.dk/GTLDK/showt...-Wheel-Buttons