[Tierfreund]

1) No. The factory will not deilver it that way. Despite not beeing a technical problem, the car will run just fine on the same size all round, teh factory will simply not do it for you because it would be inefficient to provide such a setup for one lonely customer.

2) It has no adverse effects on peformance. The standard setup on the non sports models is a non staggered (same size all round) setup. Only with 17inches instead of 18´s. The car will run just fine that way.

Staggered setups on regular road cars (not track cars) without a monster motor and tons of torque are actually quite silly. The 330 certainly does not have the torque to NEED wider rear wheels. Actually it doesn´t do it any good. The only reason for that setup is the "sporty" look. People want the wide wheel look and since 255´s will not fit in the front wheel well, BMW offers them in the staggered setup.

But you´re out of luck with your wishes. If you ordered the sports pack, you´ll be getting the wide rear wheels. The economics of scale will see to taht.
The only thing you could do is ask your dealer to swap the rear wheels for a set of 162´s front wheels from the parts department. But he´ll charge you accordingly and that will be prohibitively expensive (you´ll be buying the front wheels and tires without any new use to put your rear wheels to)
So it´ll be easier and cheaper to just not switch front to rear.....