Perhaps my experience will help others. Sorry if this is too lengthy.
Last Monday I took my 2005 545 in for service with this comment:
"The car goes through periods where a series of shocks go through the drive train while driving. They happen when the car is running on light throttle, like cruising. They feel like rough shifts but the RPMs don’t change. It has been happening off and on for the last 6 months but has not been consistent enough to think that it would do it when brought in for service. A couple of weeks ago I noticed that it was happening in “S” mode at 60 to 70 mph almost every time. In drive mode it happens around 30 to 40 mph. In drive there will be a series of jerks and then a shift where I can see the RPMs drop. In “S” I get a series of jerks that don’t seem to stop until I move the control to drive and then I get a hard shift into top gear. The speeds are pretty consistent. I only get the jerks in drive around 30 to 40 and only get the jerks in “S” around 60 to 70. Running up through the gears with the transmission shifting itself seems normal with no rough or hard shifts. It is only in the “cruising” part throttle situation where it shows up."
I am 8 months out of warranty and used my aftermarket warranty on this car for the first time.
The diagnosis was "Issue occurs in 5th gear regardless of manual/sport drive setting. Mechatronics/valve body is faulty and requires replacement along with use of new trans oil."
The bill was $4151.81. The dealer (Crevier in Santa Ana, CA) did have to get approval from the warranty adjuster. My payment was $100.00. (Yes I was 'repaid' my warranty cost on the first use.)
I picked the car up last night and, so far, everything is normal. The hard shift when moving from S to drive at freeway speeds is gone.
The part number on the invoice is 24-34-7-571-233 and is listed as "RMFD Mechatronics" a rebuilt unit. Unit price $2919.27. Also listed is 12 1/2 liters of oil (I'm assuming trans fuid). Labor was $870.00.