Just checked my black ones. Cracked too
These are the pictures of replacing ones
They wanted mine back to return to BMW, I then fitted them myself once they arrived. I removed them and dropped them off which I was close to the dealers. When the replacements came in they gave me a call and I went and collected them. They were also happy to post them to me. Yes they are adjustable for height, but they only have two settings as to the original ones which had three positions.
do new one go as low as old one, I have mine on low setting, does it look as low new one with only 2 hole thanks