Since I'm new to the BMW world, I'm still trying to figure out what all the model numbers and designators mean.
I understand what X1, X3, X5, X6 are, plus the 1, 3, 5, 6, 7, Z4, and M, as shown on the BMW USA website.
But what does E84, F20, E87, E92, F12, etc come from? Is there a guide? Why is "X1" used in some instances and "E84" used at other times?