2005 GT problems

I have a 2005 GT that has had the battery replaced 4 times in the last year and a half by the dealership. Each time the car has been completely dead - not even able to be jumped. The dealer claims there is nothing wrong with the car because their computer can't pick up on anything. The last battery lasted less than 2 months. They claim because I only drive the car about 2-3 times a week, the battery will die. Clearly something, somewhere is draining the battery, but how do I find out what? The dealer just dropped off the car again and told me that if I bring it up there any more without them being able to find a problem, they're gonna start charging me to look at it. I'm so fed up with this car. This has been going on since a month after I bought it (brand new). Any suggestions or is anyone else having the same problem? I've hit the point that I'm ready to drop the car off at a GM dealer and tell 'em to keep the piece of junk!

Tell your dealer that you will report them and impose the lemon law against them. If you only drove the car a few miles at a time, and less frequently than 2-3times a week, then maybe I'd say teh car's normal parasitic draw is the issue, but it sounds like they aren't doing any diagnostics, just parts swapping. A simple digital multimeter hooked up between the negative cable and the battery would finger a parasitic draw, unless the issue is very intermittent and isn't occurring when the test is done.