2002 330Ci battery replacement experience
Let me start off by saying that even minor do-it-yourself car projects for me end up in a disaster so when I say this one was easy, it must be really easy.
Battery - Advanced Auto Parts 94R2. Perfect fit. No mods to battery well required. $118 (after returning old battery and receiving $10 credit)
Hardest part was removing plastic trunk tray that is over battery. Pull out the plastic plug clip that is up and to the left of the battery on the side of the trunk. That gives the gray carpet trunk liner a bit more wiggle room so the black plastic tray can be worked out from underneath it.
Note that the metal bracket in the battery well is much longer than the OEM battery. There is a little white plastic block towards the rear of the car that keeps the OEM (and then the replacement battery) from sliding front to back. Just make sure you put the battery in place so that the white plastic block is behind it.
Take the negative terminal off first
The Advanced Auto Parts battery appears to have vent holes on either side. I swapped the little black plastic plug from one side of the Advance battery to the other so the vent could be attached on the same side as it was on the OEM battery.
That's pretty much it. Oh, and you should check your spare tire pressure since you already have the trunk cover out.
2002 330Ci, Steel Grey Metallic
1999 Ducati 900 SuperSport
He who dies with the most toys...