Talk about a derailed thread ....!
If it were my car I would check to see what the manual calls for regarding power steering fluid. Some cars shouldn't have ATF in the PS system.
Regarding the rest, I like using Mobil Synthetics all around.
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)