Did a study on this. Used to be a rubber collar, but then it went to what Dan is describing - band finish. One of the members was showing a carpet being an MB spare part with band finish looking, actually, not very premium.
I never found the rubber piece. They are available for manual, but I failed to find one for automatic.
The blue interior is mine, so the finish is not, most likely 100% correct, but it should give a general idea.