The car reports its own state to the manufacturer: locked, alarm armed, doors, lights, battery. Twice a month it reports unlocked with the interior light on, for about eleven minutes, on my drive, with the keys in a tin in the kitchen.
The car is four years old and it came with an app, which I thought was a gimmick and now check more than I check my messages.
The app shows the car's status, live, from the car's own telematics unit. Locked or unlocked. Alarm armed or not. Each door, the boot, the bonnet. Interior light. Battery voltage. Where it is.
That is not a guess based on the last thing that happened. The car reports its state up to the manufacturer over its own mobile connection, and the app shows you what the car said.
There is also a history: an event list, going back ninety days, of every state change.
Twice a month, roughly, between about half past midnight and half past three, the history shows this sequence.
Alarm disarmed. Doors unlocked. Driver's door open. Interior light on.
Then, between nine and thirteen minutes later:
Driver's door closed. Interior light off. Doors locked. Alarm armed.
The keys.
Two of them. One lives in a tin on the kitchen windowsill, which is a Faraday tin I bought after reading about relay attacks, and one is in a drawer upstairs in a pouch of the same kind.
That is the first thing anybody says: relay theft. Somebody outside with an amplifier picking up the key's signal from inside the house and relaying it to the car.
I bought the tin in the second month of this and it made no difference at all. And a relay attack is done to steal a car, and it takes under a minute, and the car is still on my drive.
What is different about the ones I have seen with my own eyes.
Four times I have been awake for it, because I set an alarm after the sixth one.
The car is on the drive, ten feet from my front window, under a security light that is on a motion sensor.
All four times, at the moment the app said the interior light came on, the interior light came on. You can see it perfectly clearly: the little dome light over the mirror, and the footwells, and the whole inside of the car goes the colour those lights are.
The security light did not come on. It is a decent one and it triggers on a cat.
And there is nobody in the car. Not somebody I could not see properly: the interior is lit, the windows are clear, and both front seats are empty and so is the back.
What has been checked by people who are paid to check it.
The dealer, three times. The first two times they read the fault codes, found nothing, and updated the telematics software. The third time, in 2024, they kept the car for four days and put it on their own monitoring.
It did it on the second night, on their forecourt, and their service manager rang me about it, which is not a call I expected to get.
His report says the vehicle logged an unlock and interior light activation with no corresponding key transponder authentication recorded.
That last part is the sentence I have read most often in my life. The car unlocks when it sees a key. The log records which key. On every one of these, and there are now about sixty, the key field is empty.
They replaced the body control module under warranty. It carried on.
The eleven minutes.
The duration is the most consistent thing about it. Never under nine, never over thirteen, and the median is eleven.
I have sat in that car for eleven minutes to see what it is like. It is a long time. It is long enough to be uncomfortable and much too long to be looking for something.
It is about how long it takes to have a cigarette, which I know because my father used to sit in his car on the drive and have one, because my mother would not have it in the house.
That is not evidence. My father died in 2011 and it is a different car and a different house and I know exactly what my brain is doing when it offers me that.
The mileage.
I check it. Of course I check it.
It has never moved. Not a tenth of a mile in three years of this, and the app records the location and the location is my drive, to the metre, every time.
The fuel does not change. The battery voltage drops about a tenth of a volt across the eleven minutes, which is exactly what an interior light does, and comes back when the engine next runs.
What I have settled on, which is not a theory.
I have stopped setting the alarm on my phone to catch them. Four was enough, and the fourth one I sat at my own front window in the dark for eleven minutes looking at a lit empty car, and when the light went off I found that I had been holding the edge of the windowsill hard enough that my hands hurt.
The app still notifies me and I have not turned that off, and I have thought about why not.
I think it is because the sequence always ends the same way. Door closed, light off, doors locked, alarm armed.
Whatever it is, it locks up after itself.