I believe the wheels to be REPLICAS of the M5 wheel. There are no BMW logos or part numbers stamped on the wheel.
Specs for all 4 wheels are as follows.
Wheels: 18" x 8" ET20
Tires: Pirelli 240 Snowsport 235/40/18
2 of the wheels have curb rash (from the previous owner)
3 of the tires seems to be worn more in the center and the other 1 seems to be fairly new.
These wheels were included when I bought the car in January of this year (2006) and I don't plan on driving the car during winter as long as I own her.
Hi-Res pics can be found here:
http://clem.e46fanatics.com/forsale/winters
X = the wheel
Xa = pic of the tread at the center of the tire in relation to a Canadian quarter
Xb = pic of the tread at the side of the tire in relation to a Canadian quarter
Not sure what they are worth but I have a vague notion.
If interested please PM me.