The 2006 and later 3-series use a total of 4 different E-codes. The 1-series uses FIVE of them. No wonder BMW ran out of E-codes and had to go to F-codes. Can someone please explain to me why BMW went to this maddening system of keeping track of which cars had which chassis codes? Case in point is my E32. It had only one chassis code for all 7-series cars from the 1988 to 1994 model year, regardless of engine or body length (i or iL). If you say E32, nearly everyone familiar with BMW chassis codes knows right away you're talking about a second-generation 7-series, regardless of model or body length. I am just trying to understand why BMW went from a sensible system of applying just one code for an entire model, to a maddening one that uses as many as five for a single model. At that rate, it will be just a few years before we're into G-codes.