It seems we all have issue w/ the center armrest being too small and too low...
This is one thing I am not happy with in the xB. The armrest is to low and the window is to high for me to rest my arm there. It is like on either side it is not convenient or comfortable to rest my arms while I am driving. Of course I have adjusted the way I drive in the xB. But that is one thing I don't care for.