Buying a used car in Buckingham — the security questions nobody asks

People inspect a used car thoroughly and then ask nothing at all about its security, and we see the result on Buckingham driveways most months. The service history gets read line by line, the tyres get looked at, somebody checks the panel gaps — and then the keys are handed over without a single question about how many of them exist. It is the one part of the transaction that cannot be put right later by spending money on parts.

Ask how many keys the car has, and then physically count them. Two is normal. One is a negotiating point and a warning: it means either a key was lost, in which case somebody may have found it, or a key exists somewhere you will never trace. A used car is not sold with a certificate confirming that no other working key is in circulation, and there is no way to obtain one afterwards. The only reliable fix is to make a key insufficient on its own.

Ask whether the car is keyless, and confirm it yourself rather than taking the answer. Walk up with the fob in a pocket, pull the handle, and see whether it opens. Sit in, leave the key where it is, and see whether it starts. A car that does both can be taken by relay attack, and knowing that on the forecourt is more useful than discovering it in a month.

Ask what security has been added, and treat a claim of an aftermarket immobiliser as something to be evidenced rather than believed. A previous owner who fitted a Ghost has a certificate and a sequence, and both need to come to you. A system nobody can produce paperwork for is a system your insurer will not recognise, and a sequence nobody can tell you is a car you will not be able to start. If a seller mentions one, ask to see it demonstrated and ask for the sequence to be changed in front of you or reset by an installer afterwards.

That last point applies more widely than people expect. Anything the previous owner knew about the car, they still know. Where the spare lived, which sequence was set, whether the garage was left unlocked. On a private sale you are usually buying from somebody perfectly honest, but you are also inheriting a set of facts you cannot audit, and the sensible response is to reset what can be reset.

Then there is the vehicle itself. If you are buying something from the last decade with keyless entry, assume that the factory security will not stop a relay attack, because it is not designed to — it checks whether a valid key is present, and a relay presents one. If you are buying something older without keyless entry, the exposure is the diagnostic socket in the footwell instead, which on many vehicles will accept a device that programs a new key in around a minute. Neither is a reason not to buy the car. Both are reasons to know which one applies before it is sitting on your drive.

The practical answer is to treat security as part of the purchase rather than something to get round to. A Ghost II or a CAN Phantom takes two to three hours, goes on at the property rather than at a workshop, and immediately makes every key that may or may not be out there insufficient on its own. Doing it in the first week is also considerably easier than doing it in the first week of next year.

If you are looking at something around Buckingham and want to know what it will need, send us the registration before you commit. We will tell you whether it is keyless, which system fits it, and what it costs — and there is no obligation to book anything.