Hey forum, I have a 2005 MCLS and I am on my 4th battery for this car. I had a stereo w/2 amps and a capacitor. i thought that was the cause of the drain, so I removed the aftermarket and replaced it with the factory headunit. I am still having the drain. To back up a bit, I don't drive the car everyday or every week. If I drive it and allow it to sit for 4 days w/o starting, it is drained. I try and get the batteries charged and it says replace battery. Any help is good help.