not a dumb question, I couldn't figure it out myself either as it didn't make sense the way it's stated. So I went to a dealership, I found a M3 with the trim, touched it, and it was leather as everyone said. Interesting CF weave pattern on it.
It's by far the best trim for the M3, with the aluminum trim coming in a close 2nd. It beats the cheap plastic CF trim found in cheaper models, and looks cooler than real CF.