2 is a Coupe or Convertible. 3 is a Sedan or Wagon. 4 is a Coupe, Sedan, or Convertible (though they call the Sedan a Coupe). 5 is a Sedan. 6 is a Coupe, Sedan,

2 is a Coupe or Convertible. 3 is a Sedan or Wagon. 4 is a Coupe, Sedan, or Convertible (though they call the Sedan a Coupe). 5 is a Sedan. 6 is a Coupe, Sedan, or Convertible. 7 is a Sedan. There's a little method to the madness, though I don't know if this is on purpose. Odd numbers are the more "luxury" models, whereas the even numbers are the more "sporty" models. M-series models are only available on the even numbers, with the exception of the 3-series.