I might be mental

intrade, May 1, 11:10am
dont know do you got a alarm! mosture in sensor maybe! and do you got electric windo winders. alarm would be more likely . if the windo open has done it.

evotime, May 1, 11:17am
I guess if you reached in through the window and turned off the key and took it out of the ignition without opening and closing the door the BCM (body control module) might stay awake! depends on the car I guess.
If it only goes flat when the windows are left down just don't leave them down.

johnf_456, Dec 31, 8:57am
Could be a weak battery, colder weather brings out the best in dying batterys.