I have a '06 and I often leave the hatch open in my garage (I keep the hatch light switch off) for the convenience of loading and unloading my stuff. Last year I had to replace the accessory battery, so I got a new Exide battery in the appropriate physical size and installed it. Anyway, I have had this problem twice in the last few months: despite all of the lights, etc. being off, I had the battery die when the hatch was left open in the garage overnight. Now, I do this all the time. This problem happened twice. Keep in mind that the battery is designed to store around 500 watt-hours of energy. Even a a few watts of lighting left on in the car should take over four days to discharge the accessory battery. So either there is a battery capacity problem, a charging problem, or something is occasionally eating power when the car is off. Each time, I started the car using a cordless tool battery, but something is not right here.