Gave up on my stock battery and replaced it this morning with a new Diehard Platinum. Mine is a 2010 Roadster, built 9/2009 (I bought used 12/2010), and just turned 60,000 mi...daily driver since 4/2011. While the stock battery still had some life in it, it had gotten VERY sluggish starting the car to the point of barely turning over in the mornings. Wasn't worth it to see how much further it would go before stranding me somewhere.
Now with the fresh battery, startup is fastest I think I've ever seen in the car! Thanks to the board members how-to's on the subject, swapping the batteries was a snap!
