To make a long story short - after having my car for a year and two months (bought 1/07) - my battery went belly up. Figured no big deal, its covered under warranty, I'll get a new one for free. Took it in, service rep said that it must have sat on a shelf too long some where and it sulfurized (or some word like that). thought that was a little weird cause I bought one of the first ones out, but whatever. Anyway, the dealer didn't have one in stock. Had to go to Cerritos to get one. so I had to wait much longer then I had expected (they did offer a free car, if I didn't want to wait). But the main thing was that they said that the stock battery must go in. An after market battery would not work. Is this true? Looking down the road a bit (I tend to keep my cars for a very long time), this is a little scary. On the other hand, they didn't even have many tire choices when the car first came out and now they do, so maybe its just a matter of time. But my question is, is the battery that different?