Last Saturday, I forgot to remove the ignition key from my ’05 SL500 after parked it in my garage. I didn’t remove the key until after several hours later. On Sunday, I can’t start the car and it appears that both starter & trunk batteries are drained. I was surprised to learned that Ignition Key inserted over extended period will cause battery be drained. I called MB Roadside Assistance and they were kind enough to jump start for me. Wow! That is quite a lesson!