Connected car: removing the previous owner's account

On many newer vehicles the car itself is a device with its own mobile connection. It reports to the manufacturer, and an account accesses it through the manufacturer's app or customer portal: show the location, lock and unlock, start the climate control, retrieve trip data or charge level. That account is tied not to the key but to a person, and it does not necessarily end with the sale.

On top of that come connections that do not come from the manufacturer: phones paired via Bluetooth; digital keys on a phone; charging cards and charging contracts on an electric car; a toll transponder behind the windscreen; a plug in the diagnostic port fitted by an insurer or a fleet operator; sometimes a small Bluetooth tracker the owner hid in the car against theft.

For the buyer it is a question of security: whoever can locate the car knows where it stands at night, and whoever can unlock it can get in. For the seller it is a question of privacy and money: his data sits in the car, and subscriptions and bills may keep running through his account. So both have an interest in cutting these connections at handover at the latest.

The infotainment system of a connected car stores more than you would think when getting in. None of it is secret on its own, but taken together it gives a fairly precise picture of a person.

The last item is the one most often overlooked and the most sensitive. A built-in garage door opener with a stored code plus a home address in the navigation system together amount to the key to your house. Such codes are often not deleted through the screen menu but with a button combination on the buttons themselves; the owner's manual explains how.

For the buyer the reverse applies: whatever of this data he finds is not his. If you see someone else's contacts or destinations when you first get in, delete them or tell the seller, and do not use them.

The order matters, because two things that seem to belong together are separate: the data in the car and the link in the account. Resetting the screen to factory settings deletes data in the car, but on many systems it does not remove the car from your account with the manufacturer. Removing it in the app cuts the account link but leaves the contacts in the car. You need both.

Finally, a check: ignition on, go through the menus, phone list, destinations, profiles. Anything still there was missed by the reset. And add a sentence to the handover record saying that account and data have been removed. For the buyer it is information, for you a record.

A digital key is a key like any other, except that you cannot put it on the table. Depending on the system it lives in the manufacturer's app, in the phone's digital wallet or on a key card, and the owner has often shared further keys with family members. At the sale, all of them need revoking, not just your own. A key card belongs to the car like a metal key and is counted in the contract.

Harder are features unlocked by software: a seat heater, a driver assistance system, a navigation function, more power on some electric cars. Whether they stay with the car or hang on an account, whether they were bought or only subscribed to, differs from manufacturer to manufacturer. A purchased package may be tied to the car; a subscription often ends with the account it runs on.

For the listing, that means: only include what works without your account, or add that a feature needs a subscription. If in doubt, ask the manufacturer what happens on a change of keeper. Many connected services run without extra cost for a while from first registration and then only by subscription; a buyer wants to know that before buying, too.

Ask explicitly at handover: has the car been removed from your manufacturer account? Have all digital keys been revoked, including shared ones? Is there still a toll transponder, a charging card or a plug in the diagnostic port? The answers belong in the handover record, together with the number of keys and key cards.

Then register yourself with the manufacturer. Many systems have a primary user who grants further access, and signing up as primary user requires proof: a code shown in the car, being present with the key, the registration papers or a visit to a brand workshop. If nobody else is registered, this is usually quick; if the previous owner is still in there, it takes more effort.

In the first few days, two checks are worthwhile. First the menus: if unknown phones, profiles or destinations are still there, reset the system yourself. Second, trackers. Many phones now warn you when an unknown Bluetooth tracker is moving with you. If you get such a warning, go through the glovebox, boot and seat pockets. Usually there is no ill will behind it, just something forgotten, but it does not belong in the car.

Sometimes it only turns out weeks later that the car is still in someone else's account: the app cannot be set up because the vehicle is already linked, or an unknown primary user shows up in the menu. The first port of call is then the seller. A short message is usually enough, and he removes the car in a few minutes.

If he cannot be reached, the route goes through the manufacturer. As a rule there is a procedure for this via customer service or a brand workshop: you prove that the car now belongs to you, with the registration papers in your name and the purchase contract, and the old access is cut. The manufacturer's customer service will tell you which papers are required and how long it takes.

Until then, restrict access as far as the car allows. Many systems have a privacy or offline mode in the menu that stops the transmission of location and driving data; what it is called and exactly what it switches off is in the owner's manual. You can find a brand workshop nearby in the garage directory: businesses can state there which makes they look after. Whether and when they reply is up to them.