I know there has been a lot written about Optima batteries, pro and con, lately, but since I have had such positive results, I feel I owe them my commentary. I purchased my Cobra about nine years ago and my battery has been one of the best components on my machine. I have replaced the original FE engine (blew up), installed a Shelby 427, and then had to rebuild the Shelby, which has been running fine for ~3 years now. I've done nothing special for the battery other than move it to behind the passenger's seat, still in the boot. And place it on a trickle charger when the car was not running. Oh, I recently installed one of their cool billet aluminium hold-downs. When this battery finally croaks, I plan on ordering another Optima, in spite of the grief some of you have had.
Jim McIlvaine (OptimaJim) is their eCare Manager and he has written well on the subject. You may want to send him a private message. Rich