I'd option it this way:
Space Saver Spare - $150 (you can go to run flats later if desired)
Roof Rails - $100
Smartphone Integration - $150
iPod and USB Adapter (can hook different devices to it, not just iPod) - $400
BMW Assist w/Bluetooth - $750
Rubber floor mats - $74
The MSRP is 54,299. With the incentives, and your BMW drive $ and some smart bargaining you should easily get below 50K...Even though you won't use Assist it's free the first year and then you can opt to not have it; but the BT integration is really a smart feature.
Even though you may not need some of that now - having it there for a low entry fee makes sense in my mind then wishing you got it later as adding options is really a pain after the fact or impossible.
FWIW - I also ordered (separately from the car) the mud flaps and had them dealer installed as well as the 3M clear mask on the front.
My .02 cents but good luck, you'll love the diesel.
