I've just tried changing this (tried changing it to US). No noticable differences when driving, and when i look back at the screen, it's reverted to Euro RH.
When setting it to US, it didn't make the US-"hidden menu" available then, I take it?
Useful maybe.. but what it's useful for is another matter ;)
L.
When you say the US hidden menu, do you mean the one from the volume screen (top left, bottom, left, etc..) ? If so, not tried it yet but will try tonight.
Steve