Assuming you have a ZF 6 spd it takes Lifeguard6.
Go to realoem.com and check what transmission it is.
I think you can find it at a dealer and it takes most likely 5-6L with no filter change. Just open the fill port to make sure it can be opened, open the drain port, drain out the fluid. Plug the drain port, fill the fill port (you need a hand pump) until it weaps out. Now start the car and allow the fluid to get to 80-120F. Once there leave the engine running and pull the fill plug and continue to refill until it weaks out. Done.
Your transmision is:
AUTOMATIC GEARBOX GA6HP26Z
from realoem.com
Here is where you can get the LG6
http://www.thectsc.com/
Don't use anything else as it appears this is a ZF transmission and they don't take well to other than LG6