Factory OEM Wheels or Replicas? How do you tell?

[MANGO]

Got around to taking off the wheels today to give them (and the brakes) a good cleaning/dusting.

As I started to scrub away at the back of the first wheel, I started taking mental notes of the various markings in the spokes. Style 168s.
I ran into a stamp that says the "Ronal" which tells me these wheels are made by Ronal the wheel company from Germany.

Then another that says "Made in Mexico"
Needless to say I was surprised. I've always thought BMW wheels got churned out by BBS, Borbet, and Ronal out of Germany.

What am I looking at here? Are these factory OEM or are they did I just get jipped with replicas?

[MANGO]

Dug around some more.

Guess I found my answer...
http://www.xoutpost.com/bmw-sav-foru...-pictures.html

[gmBH]

they are original. Mine say Ronal made in Mexico as well. But you will see "BMW' stamped on each rim