This can be a problem with any modern car. I had a similar problem with my 2011 BMW, but I was partially responsible. I added a device to the CAN bus between the entertainment system and the rest of the vehicle so my passengers could watch DVDs while we were driving. When the vehicle was off, the ECU would stay awake trying to communicate with the entertainment system, which would fail because the device I added was powered off. The car was brand new and the battery died after a month. I removed (and redesigned) the device so it would provide CAN connectivity when off, but had my battery replaced (under warranty) before I re-installed it.

It sucks that auto manufacturers don't consider the consequences of their design decisions. A malfunctioning (or missing) entertainment system should not cause the ECU to drain your battery.