Yeah, you can definitely do better. Use truecar.com to find the invoice pricing of the packages and the car and see which dealer can give you the best pricing under invoice.
Also, order a new vehicle now and there's a credit for the navigation unit (confirmed at two local BMW dealers), so you'll be getting the unit for free, as well as the AWD credit of $1840. And depending on how you configure the car, with the free navigation unit, you'll see a drop in price for the cold weather package as well. Just build your car on www.bmwusa.com
and tou can see the MSRP pricing of the nav unit to be $0 while some other packages might drop as well.
I've priced out a completely loaded 335i RWD sedan (Prm, cold, msport, metallic paint, nav @ $0, harman kardon, comfort access, and few other stuff) at $52,500 MSRP. Best price I received using truecar.com is $2314 ($1000 dealer cash and $1304 auto trans credit option) under invoice. Working out the invoice value of my configured car came out to be around $48,631. With the dealer cash and credit, it comes out to $46,317. That's over $6k off MSRP and for a new car! Definitely do your research. It can save you a few grand.