My boss has a 2005 STS 4.6. On his way to work yesterday morning, he stopped at the QuickTrip down the street from our office. Upon returning to his car with his morning coffee, it refused to start. So he walked the 3 blocks to the office and asked me for assistance. We drove down in a co-worker's car, I got in and sure enough...dash lights flickering and a faint 'click click' from the engine compartment. His battery had finally kicked the bucket, likely due to 4+ years in the Texas heat. We removed the battery (partially crammed up under the cowl on the passenger side)and headed for AutoZone just down the street. No gots. Moved on to WalMart where I surely thought they'd have something. Nada Hit the neighborhood Pep Boys. They had a Bosch that was close in size, but about 3/4 inch taller. I didn't want to risk it. CCA wasn't quite up to the OEM battery either. Boss gets on the phone to Batteries Plus. Same story as Pep Boys. For kicks, we call Crest Cadillac and they tell us to come on down. The parts guy returned from the store room and plunked down a pretty new AC Delco battery identical to the old dusty one we plunked down on his counter. Then came the jaw-dropping $217 bill. Apparently Cadillac saw fit to have this battery custom-made by Delco. No other battery manufacturer makes a battery exactly this size with exactly this CCA. Luxury comes at a price folks. I just can't figure out how this type of thing is supposed to attract customers. Imagine the bill had he 1) gotten the car towed to Crest and 2) had a technician diagnose and replace the battery. I'll never complain about the high-maintenance nature of my Mazdaspeed 6 again. At least it uses a battery that can be purchased anywhere.