hi Aeromax, I had a similar problem before on my Aero, the battery lasted a bit longer(two weeks), eventually found the boot light was incorrectly wired, therefore the light was on all the time!
May sound obvious, have you check for inteior/boot light? Also have you a hi-fi system with amp in yours? The amp might not be installed/wired properly, it could still be "ON" even the ignition's off!
