ORIGINAL: lear4406
Make sure you read the warranty and don't break any seals. I know the rear axle has a seal and the dealership is the only one who can break and replace the seal. If broken then it might void the warranty on that componant. Also you need proof of the proper oil intervals being followed as changing is concerned. Just read and cover your butt.
The other thing is if something major does go wrong, if you did it yourself whether or not it was a result of something you did, car companies have been known to void the warranty because you did it instead of themselves no matter if you have the receipts to prove it.