Recommended Fluid
WARNING: This page is about a different car, the 2005 BMW 645Ci, 2005 BMW 545i, 2004 BMW 645Ci, and 2004 BMW 545i. However, it is still accessible from the selected car via links, so may be relevant.
From model year 2004, some manual transmissions are filled with Castrol MTF-LT-2 lifetime fluid. This fluid has the same properties as the MTF-LT-1 fluid. The MTF-LT-1 fluid may be mixed or substituted for the MTF-LT-2 manual transmission fluid.