Has anyone changed theirs? i am looking at doing mine soon. I was just curious as to which oil is reccomended as I read that Audi/VW don't actually have a grade for their oil? I'm ordering from Opie so would be handy if they sell some I can use. Or I have some Millers CRX 75w-90 if that's good? Am I right in thinking its a hex key to drain and fill/level? Both torqued to approx 40nm? I've also read people saying things about how it fills the diff also etc, is there any working practice or procedure that should be followed to ensure oil is fully circulated etc. thanks.