One problem related to ignition has been reported for the 2006 BMW 325. The most recently reported issues are listed below.
I just purchased a BMW 330 with an option called "comfort access". This option allows the driver (with the key on his/her person) to unlock & start the car as well as and kill the engine (by pressing the start/stop button) & lock the vehicle, all without using a key. . . . Just need it in your pocket etc. The risk is that you can exit the vehicle and lock the doors w/o killing the engine. My concern is being distracted or forgetful and leaving the car running in our garage and having exhaust fumes enter the house! a simple fix would be to have the engine stop running when the driver exists the car and/or locks the doors from outside of the vehicle.