Out of curiosity, I looked up the number of 2012 '3' series currently advertised on Carsales, as a
indicative/rough guide measurement of what models 3 series customers generally want. The findings are not surprising but gives you a good idea of 80% these customers really want.
Note: includes E90 generation coupes
Model Qty Perc My comments
320d 264 52% Want value for money, diesel motor makes good power and saves fuel costs
318d 85 17% Really budget conscious, don't care at all about performance
320i 77 15% Don't like diesel motors
328i 55 11% That's people like us
335i 19 4% Those who have a bigger budget and want the ultimate 3 series
325i 10 2% Mid range 3 coupe
335d 2 0% If you wanted top line diesel, you'd prob buy a X5
Total 512 100%
If you added up all the entry level models (i.e. cheaper than 328i), that's accounts for 83% of 3 series. 328i/335i petrol-heads are definitely in the minority