OK, so I've driven the BMW yesterday. Drives very nicely, as I was expecting. Rather comfortable as well. But I disliked the interior usability a lot. The iDrive is incomprehensible (and I'm a CS student, for crying out loud), Audi's MMI and Merc's COMAND are much more intuitive to control, and in general many controls tend to be slightly more complicated than they have to be. Barely any room for stowing stuff, none at all in the back. GPS only shows arrows, no map view - on a color screen in a 2009 car, wtf? Also, no bluetooth in this one car. So it seems I'm not buying the 320d xDrive after all... Merc test-drive up next, tomorrow, from what I've seen so far it seems to be the best option.