There's a part of me that wishes I knew more about cars. I can usually find the dipstick and top up my windshield wiper fluid, but if you want to talk about piston rings, head gaskets or struts, I'll nod knowingly -- a practiced skill -- while secretly wishing I was a bit less ignorant when it came to mechanical stuff.

Chances are, if you have a car, you've left a garage wondering, "Did I pay too much?" or "I wonder if I really needed new struts, plugs and that air freshener." We rely on mechanics for their expertise and since most of us know so little, we often have to defer to that expertise. It's not like we can diagnose and fix most things ourselves.

That's why the annual Automobile Protection Association investigation into the integrity of the car industry is important. This year W5 again teams up with the APA to document the work of mystery shoppers -- savvy and knowledgeable car buffs themselves -- who visited 30 repair shops in Calgary and Toronto to see just how honest and capable mechanics are.

Here's how the survey works: three test vehicles are inspected by APA mechanics and deemed to be in excellent working order, with new fluids and up-to-date maintenance. Then, a single, easy-to-fix problem is created: a battery cable is loosened. It's something that could cause an intermittent starting problem. At the beginning of the survey, the mystery shoppers were concerned that this problem was too easy to spot. As you'll soon see, they were wrong.

Equipped with their own hidden cameras, the APA shoppers took the cars to auto repair shops. Their instructions are the same at each visit. They tell the person at the counter that the car starts intermittently and that they'd like a general inspection. There was a wide spectrum of recommendations and estimates. Here are some of the highlights:

The first Toronto garage the mystery shoppers visited was an Active Green and Ross. Active Green and Ross is a large southern Ontario chain of franchises -- with 90 auto centres. At this centre, a mechanic found the problem -- the loose battery cable. But when the shoppers returned after the inspection was done, instead of talking about the starting problem, the mechanic wanted to talk brakes. For 30 minutes, he shows the mystery shoppers why they should be serviced. With the car on a hoist, he points out different things. He says there's rust on the rotors. He says they're dry and need to be lubricated.

"Service the brakes," he says. "You're gonna save a lot of money."

And then he does a demonstration to show why the brake fluid should be flushed and replaced. He takes a sample of the brake fluid and pours it on the concrete floor. Then he takes some new brake fluid -- right out of the container -- and pours it next to the "old' fluid.

"Look, see how dirty?" he asks. "See the difference? Black and green."

Brake fluid gets darker than its pristine green version within days of running through your car's brake lines. It doesn't mean it's not working. In fact, in this case, the brake fluid was only a few weeks old and had been tested just a day before this visit -- testing fine.

But since the shoppers were posing as regular customers, they deferred to the mechanic's expertise after he says, "Yeah, you gotta do a brake fluid flush too ... Otherwise, you're gonna damage all your hydraulic (sic)."

So, the garage does the work -- a full brake service and fluid flush. Total bill: $404.

George Iny is director of the APA. He and a mechanic reviewed the work right after the visit.

"We actually took the brakes apart and took a look at them… You could see that a machine had been used on the brakes but only on the outside, the part you could see… They used the wrong kind of product on the back of the brake pads…We checked our master cylinder and it had been overfilled and so what that would do in the long run is possibly provoke a leak coming out of the cylinder."

This garage was given a failing grade.

Peter Steele is the general manager at Active Green and Ross. We asked him for an on-camera interview and he wrote us, "We require disclosure of all of the information you hold in regards to the APA mystery shoppers…as the information we have differs from what you say was said."

W5 sent him invoices, a summary of what happened and offered to share the undercover shopper video in an interview. He declined our offer, but said Active Green and Ross rarely receives customer complaints and closely monitors its franchisees practices.

"If there is a problem, we want to know about it, verify it, and ... fix it."

All told, out of the 11 repair shops the APA visited in Toronto, only one got a passing grade -- an Active Green and Ross -- which found the cable, charged a reasonable amount and correctly told the shoppers that everything else looked fine.


With those dismal results in hand, the survey moved to Calgary next, where the shoppers visited 19 repair centres. The car was once again given a clean bill of health from licenced mechanic, overseen by George Iny from the APA. It was once again deemed in "excellent" condition.

At a Canadian Tire store, a service advisor told the mystery shoppers he recommended their battery and spark plugs be replaced -- though both were perfectly fine. The work was authorized at a cost of $507.48 -- the biggest bill paid by the APA in Calgary. As for the spark plugs - that's another story. Remember, the mystery shoppers always ask for their old parts back. When they asked for their plugs, they had to wait and were then returned a different set of plugs. They actually could not be re-installed on the test vehicle, because they wouldn't fit.

We reached Canadian Tire spokesperson, Liz Hamilton. She wouldn't agree to an on-camera interview, but sent us a statement, saying Canadian Tire was "committed to operating with integrity", "we stand behind the work we do" and are "fully accountable to our customers." She added that " no time was the mystery shopper told that recommended work was required when it wasn't. At no time was work done that the shopper did not authorize to be done" at any of the Canadian Tire locations.

It's true that the mystery shoppers approved all work that was done. But does that legitimize unnecessary repairs? The Automobile Protection Association doesn't think so.

"They don't tell you it's an emergency, says the APA's George Iny. "They'll tell you it might be necessary. The fact is, if you said okay in response to a cocktail of misrepresentations, deceptions and truths all mixed up together, then in a sense, you're okay isn't a clean okay. It doesn't get them off the hook."

Out of all the repairs shops that were given a failing grade and contacted by W5, just one agreed to an interview. Rick Ball owns a Fountain Tire garage. One of his mechanics replaced a battery -- which tested fine both before and after the visit. Ball took full responsibility and his was the only shop that W5 contacted that offered to give back the APA's money.

"I don't like the fact that we made a mistake," says Ball. "I'm beside myself. I've been in this business so long and this is one thing I absolutely do not like about our industry -- that things go wrong, people get sold the wrong things and I just feel terrible about it."

But there were few bright spots in this survey. Overall, for both cities, 22 out of 30 shops were given a failing grade -- for either not spotting the loose battery cable, or for doing unnecessary work.

What can you do? A lot of places offer free or cheap inspections. Take advantage of that. If you get an outlandish estimate or just have a bad feeling, go somewhere else and see if they have the same opinion. It's a bit of a hassle, but it could save you hundreds of dollars.

Or you could enroll in a mechanic's course and install a hoist in your driveway. Though your neighbours might not be so impressed.