I've had very good luck with Interstate batteries, especially since I go directly to a distributor outlet where you can get cheap "blemishes" seconds. I had the FSR problem in my X and went through 3 batteries, each time they swapped out my abused battery, no question, no charge.

Do yourself a favor though and check some simple things: make sure your fan blower is not running even after you turn off the key (FSR prob). Also check to make sure all your courtesy lights turn off when the doors are closed. The ones in the liftgate in my X melted and caused a direct short, due to a faulty switch in the latch mechanism keeping them on all the time. Good luck