I think the reference is to the pivot bearings for camber correction. Left is 31216876849 and right is 31216876850.
I had the same question! Reading between the lines a bit, I assume it is a euphemism for a hub that alters the camber. However, a quick search of Outmotoring shows only one OEM hub for the F56, which comes in interchangeable (L/R) pairs. That doesn't match pictsidehe's comments, though, so I'm still a bit puzzled.
They are hubs with altered dimensions to change the camber. They are intended to be used after an accident, when mounting points aren't quite where they used to be. Minis have no way to alter the front camber. Hubs are available in standard, +0.5° and -0.5°. I had heard that the GPs use the crash hubs, but not the SE. Some cars have 'crash bolts' that can alter camber, but likely cost a lot less. Gone are the days when you used tools to fettle stuff. It all has to be bolt on, now. Autocross rules in street class stipulate that only factory methods can be used to alter camber.
I forgot the brand of the pieces I have on the front of my 128i. they are basically a shim between the top of the strut and the car with a slight wedge. That gets me -1.5 deg camber. It is a compromise for street and occasional track. The Cayman has -2.5 which again is too little for track, and too much for street. That's why it is a weekend toy. The PCA group I play with hasn't gotten to the point of classing cars with such detail. The BMWCCA by me also is pretty loose with the alignment. We grid by class, then number. The guy behind me has the same car, a few years newer, and a bit more modifications. If we swapped cars, he would still crush my time. I have too much fun trying to break the rear loose to care about my time. The applause from a great spin is more rewarding than a quick time!
