They now offer a dark wood trim...if darker is really your desire, you could probably swap it. Hard to say how well the existing wood trim would respond to stains. FWIW, this wood, and some notable others like cherry, can significantly change color through UV exposure. BMW acknowledges this and if I remember, mentions it in the owner's manual. I do believe that mine is lighter now than when I bought it. Leaving something in that well could leave a pattern, if it is there for any period of time, because it will likely block the UV's bleaching action. Cherry darkens with UV exposure, not bleaches out, but that's not an issue with our cars.
