What Oil do i need for my Transmission

[Multibeemer]

Your're right, there have been quite a few threads on this subject. I've gone through them, and now understand that BMW part 83229407807, ESSO LT71141, and VW/Audi G-052-162-A2 are all the same thing, or at least are all compatible. But I have one follow-up question - I did a Google search on the VW/Audi fluid, and got a link from Redline which claimed that their D4 ATF meets or exceeds the specs of the other two fluids. I did a search on Redline D4 on this forum, and nothing came up. What are the opinions of this ATF? It's considerably cheaper than the VW/Audi fluid (about $10 a liter vs. about $15), but of course if there's any doubt, I'd gladly spend the extra five bucks a liter for the peace of mind. My X5 has 78,000 miles, by the way, and isn't exhibiting any transmission issues; I'm just interested in doing a tranmission flush as preventative maintenance. Thanks.