What happens if a pre-purchase car inspection fails to pick up an issue?

When Jake Matthews bought his car he was keen to do everything right.

It is, after all, one of life's big purchases and buying a used car is not without risks, which is why Matthews got some expert help.

He paid around $200 to get a pre-purchase inspection done with the AA, the New Zealand Automobile Association.

Question is — what do you actually get for your money? Can you expect this inspection to spot every issue?

Matthews' car was a 2004 Subaru Legacy, bought from a private seller on Trade Me Motors, for $4200. The owner took the car to AA's Kapiti branch to get checked.

It's important to note that the purpose of these inspections at AA is to communicate the overall condition of a used vehicle on the day it is looked at. The inspection is based on external checks. In other words, inspectors don't take the car apart. And, if they can't determine the cause of a fault, the customer is told that further investigation is needed.

"I had full trust in the AA that they'd do right by me," Matthews said.

The only issues that were picked up were a faulty battery, surface rust starting on the under body, and some other minor faults that could be easily fixed.

"I thought OK AA seems to think this is fine, so I'll go ahead with the purchase and we should be OK."

But when he got home and tried to lock the car, Matthews realised that the key fob was only locking the driver's door and the boot. The central locking system wasn't working, and that was just hours after the inspection.

Matthews can manually lock his car, so it's not a major issue, but he wanted to know why it wasn't picked up at the inspection.

A week later he took his car into a second AA branch for a full service, which is more thorough and more expensive than a pre-purchase inspection.

"It found that three actuators had actually failed, the rear wiper fluid was not spraying, picked up surface rust under the car and a sump oil leak.

"The CV boot needed to be replaced and just a brake flush needed to be done as well," Matthews said.

The surface rust and sump oil leak didn't need to be fixed right away, the CV boot and brake flush were relatively cheap to fix, but the locking system and rear wiper washer, not so much.

"The central locking system would be $1513 to replace and then the rear wiper fluid repair would be round about $600," Matthews said.

The three actuators that needed to be replaced are what made the job so costly. They sit inside each door and operate the locks.

"It was quite a shock when I got that bill."

A shock because he bought the car based on an inspection that gave him assurance this car was good to go.

"If I'd known about these issues then I absolutely would have steered clear of the car."

Matthews did go back to AA Kapiti and it admitted that it may have missed the rear wiper fluid fault but: "They seem to keep claiming that the locks were working on the day of the inspection, which yeah, I find it hard to believe," Matthews said.

Fair Go wanted to know if a pre-purchase inspection could miss the fault with the central locking system.

Also, could three actuators really stop working in a matter of hours?

Fredco Motors' owner Craig Draper said it's highly unlikely.

"Progressively actuators on those car model's are troublesome, so it is not uncommon for the actuators to fail, but it's highly unlikely that all three actuators have failed within a matter of hours.

"I think it would be fair to say that the central locking system is probably quite easy to miss.

"The opening and closing of all the doors would definitely be checked, a thorough inspector may go that extra bit and check the central locking," Draper said.

It is worth noting that on an AA inspector's checklist there's no box for the locking system, so should there be an expectation for it to be picked up?

"It is very hard to pick up on everything on every single car," Draper said.

"Every inspector may miss things, it's just human nature and not everything can be seen and there are mistakes made."

Draper said if you have issues with your car after an inspection, your first recourse should be to take it back to where you got it checked.

"Say 'look, I've bought this car, it's now been discovered that we've got some defects, and how can we resolve the issue?'".

Fair Go asked AA's head office whether it was satisfied its Kapiti branch inspectors checked all the locks of the car and also asked how they were checked.

The AA explained that electric systems can fault at any time, intermittently, and, over a short space of time.

It also said AA Kapiti inspectors test central locking by activating the locks and manually checking that the doors lock and unlock. AA's head office said those manual checks did not happen.

General manager of AA Motoring Services Kyle Lincoln said: "We sincerely apologise to Jack Matthews for this error.

"NZAA franchisees strive to deliver a quality service to all customers, and where this hasn't happened, will always work with the customer to put things right.

"AA Kapiti are committed to doing this, and understand they have offered to assist with the issues outlined and are hoping to hear back from Jack on this."

AA's head office has since changed part of its response, stating it received further information that AA Kapiti's inspector reiterated that they did, in fact, carry out the proper manual checks.

And a great outcome in the end — AA Kapiti have been in touch with Matthews and will fix the issues with his car and cover the cost to repair the central locking system fault.

Matthews said he is well pleased.