See, we bought these four-door sedans to haul people and stuff around. The extra space in the backseat is nice for passengers and allows for four more inches of crush zone if some idiot slams into me from behind. My M coupe does not do so well hauling more than one passenger, and though my ferrets dig the coupe's cargo area, the dogs seem to prefer cruising in the 7 (maybe be a style thing with 'em?). Finally, in the case of the 750il, that's all we could get in the States (no 750i).