Just the rubber?? Like they expect you to glue the glossy piece on to it? I don't think that's gonna work. I tried removing the glossy part off of my old ones, and trust me, they are more than just glued on there. The plastic and rubber is interwoven to the point that you will really warp and damage the glossy liner in the attempt to separate it. Take my advice, it is not worth the effort, even if by some miracle you manage to pull it off (pun intended)
I would just go with this one:
https://www.fcpeuro.com/products/bmw...ck-51367891912
I know, it's a hell of a lot more expensive than the ones you got, but it's worth it if you want uniform glossiness. Or, of you don't really care, you could just use the ones you have and save a couple hundred dollars.
If someone else knows better, please correct me. This was my experience.