The European market has to deal with the new WLTP emissions requirements and this is causing problems for certain manufacturers, including BMW. The solution has been to add an Otto particle filter, but sometimes there isn't any space or the parts aren't available due to the inventory shortages and in some cases the performance is effected too much. In the case of the F80 M3, production is being stopped entirely, by the time a fix could be in place, the new G80 M3 will be coming out. The M760Li xDrive will lose the N74 V12, and the M550 will have its production halted temporarily while the Otto Particle Filter(DPF for diesels) solution is finalized. This shouldn't affect the US market since the WLTP is a European emission requirement. Interestingly enough, the F90 M5 is not affected, as the S6344T4 apparently already meets these requirements.