The Ferrari 458 is a beautiful machine, but it’s not the ideal choice for a man with two young children, a wife who likes to garden and a daily commute through stop-and-go traffic.

I mention this in light of a recent phone call from a reader who has convinced himself he should get a 458, despite its obvious limitations. His children would have to be carried on a roof rack, for example. There’s no chance that four trays of seedling plants will fit in the trunk. And the price tag will delay his retirement by four decades or so.

But the 458 has a hold on this reader, and it may take him a while to realize that he actually needs a minivan or small SUV instead of an earth-pawing stud car.

It’s a familiar pattern. As a driving columnist and ex-mechanic, I get a lot of calls and e-mails from people who want to know what car they should buy. In theory, it’s simple: I ask them what they’re going to do with the car, determine their budget and make some recommendations. Then comes the human factor.

Following the logic of a car purchasing decision can be like tracing the path of Bilbo Baggins on his labyrinthine journey through Middle Earth in J.R. Tolkien’s The Hobbit. The car-buying process usually starts logically enough, with a look at things like sticker price, trunk space and fuel efficiency. But it is soon derailed by vanity, prejudice and magical thinking – what else could have convinced one reader that she needed a Cadillac Escalade for solo shopping excursions, and another that a Caterham Seven was the perfect commuter vehicle, even though it doesn’t have doors?

Actually, that last example was me. But never mind that.

In the interest of logic, I’ve been thinking about creating an online vehicle purchasing guide that will act as a digital concierge: By answering a series of questions, you will be guided toward a short list of vehicles that will match your needs.

I tried a prototype system on some friends. The initial questions focused on a buyer’s mission (number of passengers, luggage requirements, commuting distance, etc.) and their budget. In theory, this should work perfectly. But of course, it doesn’t.

After going through the first few questions, one friend was clearly identified as a minivan candidate. (She and her husband had four kids, a cottage and a dog.) I recommended a series of vehicles that included the Honda Odyssey and the Toyota Sienna.

But it was no go.

“My college roommate has a Sienna,” she said. “I don’t like her house. And she married a jerk. How about a BMW? I like those.”

So a BMW 5-Series made perfect sense. But only to her.

Next, I tested out my system on a friend who takes a lot of long trips carrying sporting equipment like scuba tanks and bicycles. I asked him how important fuel efficiency was to him. “Very,” he replied. My database suggested a Toyota Prius or a diesel-powered VW Golf – both fuel-efficient hatchbacks with large cargo compartments.

My friend went silent for a few seconds. Then he asked me what I thought of the Dodge Ram Laramie Longhorn pickup truck. “If I need to pick up some plywood, it’ll be perfect.”

I pointed out a salient fact – he’s never actually bought a sheet of plywood in his life. But I knew that didn’t matter. The left side of his brain was temporarily out of commission. It would probably be reactivated only after he bought a giant pickup truck.

This was one of the conversations that made me realize that my car-purchase database must be redesigned so that its logic parallels that of the human mind. I’m still working on it, but the new version will probably start off something like this:

• Are you male?
• Do you possess at least some of your own hair?
• Do you take any medications that aid sexual performance?
• Were you beaten up at recess in elementary school?
• Are you independently wealthy?

There will be many more questions, but you get the drift. For many of us, car buying is not a logical process. Instead, it’s a quest that leads us toward a private vision (no matter how stupid it may be.) Some drivers long for a monster truck. Some want a Sixties muscle car. Others hunger for a Bugatti Veyron ($2-million, top speed 400 km/h).

I have to admit that my own automotive dreams – which centre on small, elemental sports cars – can seem pretty misguided. But I know where they come from: When I was a teenager, I watched a modified Lotus Seven blast up a mountain race course in British Columbia and I’ve wanted a car like it ever since. The Seven is my muse and inspiration, even though it’s a ridiculous vehicle by any conventional standard (the pedals are so small that I have to drive it in sock feet, and the red-hot exhaust pipe runs along the side of the car like a mobile branding iron).

Years of self-analysis have made it clear that small sports cars are a weakness for me. So when I go car-shopping, I keep this firmly in mind. I may have veered into the Lotus showroom from time to time, but when it was time to write the cheque, I always ended up with a reasonably priced car that could carry my family, some building supplies and my hang glider.

Some of my acquaintances have been a little less rigorous. One bought a Porsche 911 GT3 just because he always wanted one. Another came home with a tricked-out Z06 Corvette that he could barely make the payments on – as impulse decisions went, this was the automotive equivalent of marrying a teenage stripper with links to a biker gang. (He sold the Corvette a year later.) That was a while ago. Now my friend is car-shopping again. I suggested that he take my questionnaire, which would no doubt lead him directly to a Ford Taurus. He said he’d think about. But I know he won’t.

Oh well. Give a man a fish and you feed him for a day. Let him buy a Ferrari, and he’ll eat Kraft Dinner for the rest of his life. In the meantime, I’ll working on my buyer’s guide and thinking about my next car – ideally a small, fast one that looks like the ones that zoom through my dreams.

For more from Peter Cheney, go to facebook.com/cheneydrive (No login required!)

Twitter: Peter Cheney@cheneydrive

E-mail: pcheney@globeandmail.com

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