Thanks everyone for chiming in. I purchased the following battery today: AutoCraft Platinum AGM H6 battery. This is rated at 70Ah and 760 CCA (the same specs as the AGM OEM battery on realoem). As can be seen on the Advance Auto Parts site, they are running a 15% discount through March 22nd (though I was told that they are always running some type of special) so I purchased this puppy for $158.03 out the door and taxes inclusive - versus the original price of $171.99 before taxes. To put things into perspective, the dealer's OEM 570 CCA battery is going for $215, and with my BMW membership discount it only came down to $175 (still $3 more expensive than the superior 760 CCA battery that I just purchased). Size is perfect, the battery works like a charm, no transport mode hiccup…all I had to do was re-enter the date and time, and reprogram my windows for auto-up. Here's the link:
http://shop.advanceautoparts.com/p/a...rm=agm+battery
I was also considering the recommended Duralast counterpart (built by Autozone). This had a price of $161.99 and no incentives to my knowledge, even though the website is advertising 20% off any purchases of over $100. I decided on the AutoCraft because the Duralast is rated at 730 CCA, and I wanted to go with OEM numbers; this battery, however, has great reviews from forum members, as can be read a few posts above. Even though it is rated at 30 CCA less than the OEM AGM battery, it actually has 160 CCA more than the non-AGM OEM battery, which is rated at 570 CCA.
Can't go wrong with either one!