Ball polished "Challenge" wheels are a currently available option. "Challenge Stradale" wheels shipped before the ball polish finish was available. Having said that, they are the same wheel, just different finish.
If you look at my profile picture, you will see the CS wheels in ball polish. They are absolutely awesome. pictures do not do them justice!! Joe
OEM CS wheels are not Magnesium. They are one piece cast and relatively heavy. OEM lug bolts are Titanium.