After first fluid flush (about 75% of Dexron IV was gone) I felt nicer shifts and shudder was just a vibration alike @ a t higher rate,but once cold it would shudder even stronger than before the flush--> low fluid level 'cause as soon as the temp was up it would shudder as I described above.
Then I brought it for the next flush and I gave a good description of all the symptoms and gave an example from Bimmerfest board,where guy topped up the fluid by himself after tranny flush done by the shop and was able to fill one more quart of fluid,so.....Yesterday I picked up my X and drove home,no shudder at operating temps and this morning,no shudder while cold.
Mobil Super MultiVehicle ATF LT 71141 made a difference and the tranny master mechanic was refusing the idea that the fluid would change anything,he admitted that the fluid made a difference.
I may be rush to be happy about the shudder absence,but for now I am happy not to feel that frustrating thing.
Will keep you posted.

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e53 '00 4.4i Oxford Green II Freshly rebuilt tranny(2nd one) and transfer case/front shaft
e70 '08 3.0si Sapphire Black cinnamon leather 7 seats
e61 '06 530XI Sports Touring Silver - SOLD