OK, I give up. I spent a bit of time trying to figure this out. I looked in the Owner's Manual, I looked throughout the $130 Bentley I just bought. I want to change the fluids in my "new" 1991 200q to Redline. I know this much: 3.4 quarts/3.2 liters of Redline MT-90 into the transaxle, but how much of the Redline 75W90 do I need for the rear-end? Thanks!