i emailed motorsport-tech and this is what they sent me back:
Your Car is 5x120 72.56mm and the wheels are 5x120.65 70.3. You need the adapters because the hub diameter on your car is larger than the centerbore on the wheel.
Most guys go with a 20mm thick adapter which ends up putting the wheels flush with the fenders. The Saw Blades have a higher offset than what the BMW takes so you need the thickness of the adapter anyways.
The cost would be $325 shipped for everything... All four wheel adapters that are hub and wheel centric, the 20 flush mounting lugbolts to attach the adapters to the car, the 20 Lugnuts to attach the wheels to the adapters and shipping.