The steering wheel trim on my car was a bit worn along the right hand spoke where presumably the previous owner had a habit of resting their thumb and rubbing the spoke. This had left a slightly ugly shiny section where the rest of the spoke was a satin texture. I ordered a new trim from Cotswold BMW and although it was a bit pricey at £52.44, I felt that it was worth it as I would see that worn trim every time I drove the car.
There are detailed instructions on how to replace the trim on this website.
Some pictures below showing the part which was replaced.