The ABS was non functional when I bought my '08, and the PO had put a piece of tape over the indicator lights, so the selling dealer did not even know about the problem, which I soon discovered, and became a warranty situation.
The local BMW dealer would only replace with a factory module, but then both the selling dealer and myself would have lost money.
The selling dealer, the local BMW dealer and myself worked together to make a suitable deal.
BMW removed the module during the airbox recall and 20K service. I sent the module to "Module Master" in Idaho, for a full rebuild (with 5 yr warranty) and BMW reinstalled, and selling dealer warranty picked up the tab.
Module rebuild is only $250, BMW covered the airbox recall, and I paid for the 20K service