this battery discussion has been all over the forums lately. Yes you can get the H8 as mentioned above and save like $20. BUT actually the Interstate Batteries H9 95R is the EXACT REPLACEMENT the dealerships use (same size dimensionally, same ratings, vent tube hole in the same spot, even made in Germany). I just went through this a couple weeks ago. Paid $150 for the battery and $40 for registering at my indi mechanic. It is up to you whether or not you have your new battery registered.

If you search the E60 Discussion forums you see many threads about this, including my own. As a matter of fact, my local dealership was purchasing 15ea of the exact same batteries for their service dept at the time I was buying mine.

Also, removal and installation is a breeze, but it is good to have someone lend a hand to hold the positive wire out of the way while you drop in the new one. Good Luck!

 

How many miles does your car have btw? Did you ever purchase an extended warranty past the regular 4yr 50k miles warranty bmw offers?

I would just go head and have the dealership change out the battery and register it. Or have a independent shop install and register the battery for you.

As far as the transmission fluid leaking from the trans connector sleeve/seal. Again have the independent shop fix the issue for you, if you are not car smart to do it yourself.
Take your car to the dealership for maintenance will always be expensive. I would suggest you search your local area for good reputable shops that have experience working on bmw's.