The X1, X2, Y1 and Z2, not Fourier variables but future BMW models
Looks like a math teacher visited the content management system of Automotoportal. What these alphabets connote is the future range of BMW cars which the BMW engineers are working hard at.
The sport portfolio will have four models namely the BMW 1 Series Coupe, Cabrio, SuperSports and the BMW Z2 and Coupe version of the Z2.
The last portfolio, Lifestyle, will have the BMW X1, the BMW X2, the BMW Y1 and the 1 Series Gran Turismo.
Source: Zercustoms


