The transmission indicator in the X3 is one indicator of the "sleep" mode, where the computer shuts down most electronics in the vehicle to save the battery. So if you leave an interior light on or the radio on by accident, after 20min, they will be shut off. This does NOT apply to the 12V cigarette outlet. The transmission indicator will not drain the battery, nor will the flashing red light underneath the interior mirror.

No acoustical recognition of lock/unlock is possible unless you retrofit the OEM alarm system.

Bluetooth is not possible for the model year 2004 (up to/including 8/04 production). To retrofit, you need to replace the Telematics Control Unit (TCU) which is around $600-700.