My experience with mg4. When I press button on drivers door to lock the car, the horn sounds once (one honk), to indicate the check other doors. In all cases, a door or boot was ajar or open. Today my wife left her door ajar and I locked the car using driver door button. It didn’t give me the single honk I have become accustomed to. It locked without complaint. I retrieved my bag from the boot as I usually do, shut the boot and the car doors remained locked. However today the alarm went off. I opened her door, shut it and alarm turned off. Odd.