Steering wheel coverings differ

[Alberto89]

I have been wondering for a while whether different textured leather steering wheels of the Mtech variant have been produced. Mainly found in the M535i and M5. I have an M535i with relatively low mileage (so assuming my leather is not worn), and the leather on it is almost without structure (so almost smooth). I recently saw an M535i with also a low mileage, and it had very thick structure in the leather of the steering wheel. I notice that some E28s with MTech steering wheels have (smooth leather) in them (and no, not necessarily worn) and some have thick structured leather. Does anyone know what this was related to?