Reviving an old thread but I've read this on amazon reviews and bobistheoilguy

"Yes, I FINALLY got a hold of their tech dept. and they told me it is a 'plasticizer' agent which only works on rubber/EPDM type seals, and actually EATS plastic/teflon/delrin?? type seals."

Not sure if X5 used any of these materials in powersteering, engine, transmission etc.?

I got 2 bottles and put 1 in the engine and the other divided between front and rear differential, transfer case and transmission.

From some reviews on amazon they actually had their leak become worse. I'll report back if I notice any difference one way or the other.