Official Audi S2 tuner, only SMS and ABT?

[Audi-Porsche Avant RS2]

Hello friends, I want know who are official Audi S2 tuner, only SMS and ABT? I know that also MTM made the RSR, but I'm not interested in it at the moment.
Thanks!
Bye
Alessio

[UrS4boy]

I would include MTM as an S2 tuner (official or not) and then there was Scott's/Nothelle, IIRC

[Audi-Porsche Avant RS2]

Hello, I mean official tuners authorized from Audi, like SMS, ABT and MTM I think.
Thanks!
Bye
Alessio