all models look alike now... in the past you didnt see that similarity between models, but the new ones share the same characteristics.. for example, f30 tails are kinda identical to f10 tails..
and like hks786 said, there are too many models now.
series 1, coupe/hatchback/m/cabriolet.
series 2 is soon to be released as i heard.
series 3 would be the sedan 3series (f30)wagon/sedan/gt/m.
series 4 would be the coupe 3 series (f30) coupe/m/cabriolet.
series 5 has gt/sedan/wagon/m.
series 6 has coupe/sedan/M/cabriolet.
series 7 would be sedan.
x5 m and nonm.
x6 m and nonm.
27 models lol, im sure i missed a few