What is GmbH & CO.KG?

[mikhailk]

is it a tuning company for audi?

[Nordschleife]

these are abbreviations for German corporated structures, the company is the name before GmbH, as in quattro GmbH & Co. KG, or Audi AG, or even Dr. Ing h.c. Porsche AG. Germans love making it complicated and are suckers for titles, even fake, inflated, bought or honorary titles. So having a complicated set of corporate structures is only to be expected. This is probably more than you need to know.

R+C

[kartpro]

Hi, Gmbh normally refers to the Quattro company. This is the special Audi motorpsort company where the RS4 was made. So if you see anything like Gmbh brakes or so, these are the sports brakes made by Quattro.

[Nordschleife]

Hi, Gmbh normally refers to the Quattro company. This is the special Audi motorpsort company where the RS4 was made.

Be very careful describing quattro GmbH as 'the special Audi motorsport company'. The Audi motorsport company is called Audi Sport.

quattro GmbH's main income comes from customised car interiors, clothing and lifestyle accessories, 'go faster' trim and then the low volume cars, to date the S6+, the RS4 and the RS6. When it comes to customised interiors, quattro GmbH makes Porsche look cheap, they admit to pricing for the Middle East market.

R+C

[lelion]

Yes, GmbH is not exclusivity for Audi or Quattro. This is an abbreviation that explain the "constitution" of the entreprise / society.
In France for example, SA = société anonyme = anonymous owner of the society (with actions)
In the same example then XYZ inc...