I too had trepidation about the light interior but the black looked less appealing, and besides, it's primarily my wife's car, and she's not grimy like me.
The night before purchase I saw on the dealership's site a Galaxy Black interior was listed. I dug up pictures of the light steering wheel with the otherwise dark seats and my wife about choked, nope, can't do that combo.
Closing time phone call to the dealership confirmed that that was a listing error, it's really Lunar Grey, and all ended well.
My fingers are crossed that we can keep it all bright with a minimum of fuss, because it looks fanatic.