It is true that you end up seeing the interior of the car far more than the exterior as an owner, but I think the exterior is just as important. I know its vain, but art of the reason why you get a luxury car as opposed to a clunker is because of the way it looks when passersby look at your car. I don't want people to think I have an ugly car even if the inside is remarkable. I also like the back end of the MKZ but I think the front end could use a second look maybe.I think I agree - I'd say right now the front of the BMW is a level higher (most likely because we are all just used to it and BMW hasn't changed the look in decades, so it's iconic) but the tail of the MKZ is much better.
At the same time, as an owner, while exterior is important, 99% of the time, I'm looking at the interior.