I have extended leather on mine, black and red with red stichting which i guess is glued on (havent checked but would think so).
Previously on a 3 series i carbon wrapped the trim as i knew it was easy to peel off if i wanted to revert back (3m di-noc is the best) so i would say dont waste time and money looking for spares, i just need them bcos of the leather.
Alternatively if someone fancys a part ex let me know