Volvo 17" Mestra wheels, they look really nice painted black or dark grey too. Saw quite a few painted ones when I was shopping around. So you checked out the swedespeed forum? Pretty amazing how many wheels Volvo makes huh? Their reference guide is good but it does need to be updated with the newer wheels.
These are also the lightest Volvo C30 OEM wheels at 21 lbs each.
I don't have a scale (i'm just fat and I accept it and don't worry about it.) but I wanted to compare the OEM transit wheel/tire combo with the Volvo wheels and tires. The old lift test had them about the same.
Oh and for everyone else that wanted to check out that swede speed classified section for wheels and tires:
http://forums.swedespeed.com/forumdisplay.php?48-Wheels-Tires-Classifieds
Check out their Wheel image sticky at the top of the post.