Expert tips for buying a used car

Buying secondhand shouldn't be a lottery. Here's a commonsense check-list.

If you think shopping for a new car is hard, buying a used one is a far greater challenge. Get it right and you could enjoy years of affordable, mostly trouble-free motoring — get it wrong and you could be in for a nightmare ride.

An advantage in buying new is that the car comes fresh from the factory and it's the same as the next one down the production line. Every used car is different and has to be assessed in that light.

For starters, they may have been checked and serviced regularly or neglected, garaged or left in the elements, or possibly been in a crash.

They differ by virtue of the driving habits and locations of the various owners. Country cars driven on gravel roads might suffer sandblasting of the paint while in those used near the coast rust is more prevalent.

Buying a used car doesn't have to be a lottery. By understanding the potential pitfalls and following a few basic guidelines you can markedly improve the odds of coming up with a winner.

Where to buy

For a new car, there is only the dealer. For a used car, there are also car yards, auctions or private vendors.

If the car is yours when the hammer falls, there's no warranty and no comeback.

Buying from a dealer is the easiest and safest but generally is the most expensive. Dealers have to cover expenses such as rent and wages, always detail their cars so they present well, and by law they have to provide a warranty with every sale — and that extra cost is usually passed on to the buyer.

Against that is the benefit of a cooling-off period (where applicable) — you can get out of the deal if you change your mind. The dealer also has to guarantee that the vehicle is free of encumbrances such as finance, isn't on the written-off register and the odometer reading is correct.

There's also the important advantage of being able to trade in your current car, eliminating the potentially frustrating process of selling privately.

Buying at auction has to be the least expensive. You're effectively buying at trade price alongside dealers.

The downside: you can inspect cars before the auction but can't drive them. If the car is yours when the hammer falls, there's no warranty and no comeback.

Buying from a private seller also has its pitfalls. You have to take the vendor's word as to the history of the car and there's no recourse if you're not happy with it after handing over the money.

The advantage is that you can haggle and get a lower price, usually somewhere between trade and retail. Most private buyers will let you drive the car.

Extra caution is needed. If the seller suggests meeting in a public place, car park or shopping centre, be wary — if the seller's house is tidy, it is a good indication the car has been cared for.

What to check

Murray Aitken, a 20-year veteran of the used car trade, says there are numerous things to check pre-purchase. Foremost is a current roadworthiness certificate.

"It's almost impossible to write up a dodgy roadworthy these days," Aitken says. "There is so much oversight of roadworthy testers now that it's not worth them cutting corners."

Buying without that paperwork means taking a huge risk and could end up being a costly mistake.

Next on Aitken's must-do list is the condition of the interior. There should be no rips or splits in the trim, it should be clean, and there shouldn't be any odd smells.

"A clean interior tells you the car has been well looked after," Murray says.

Next, lift the bonnet and cast an eye over the engine. It should be clean and there shouldn't be any leaks visible.

Tyres tell you a lot about a car and its suspension. If all is in order, the tyres should wear evenly across the tread surface — wear on one shoulder of a tyre shows the wheel alignment is out, for example.

When checking the tyres, don't forget the spare — it it's worn oddly, look again for which corner of the car it came from.

The condition of the body and paint can also tell you about how a car has been treated. Bumps and scrapes show the driver hasn't been very careful (and that could extend to other areas) and can be expensive to repair.

Faded or blotchy paint suggests a lack of attention and exposure to the elements rather than being garaged.

The fact is that cars wear more as distances climb — but one that hasn't been driven much can be costly, too.

When checking an SUV look for scratches and scrapes along the body sides that could indicate bush use. Check also for damage to the underbody from use off-road.

"Few SUVs ever go off-road, so if you suspect a car has been used that way, walk away from it," Aitken says.

Regular servicing is the key to a long trouble-free life for all cars, so check the service book, which should have a record of regular maintenance.

If all stacks up take the car for a test drive, listening for odd noises from the engine or suspension, and pay particular attention to the automatic transmission.

Most car brands in recent years have begun to fit new types of automatics, such as the dual-clutch and constantly variable transmission.

The theory behind the technology is wonderful but the execution hasn't been without its problems. There have been serious issues with the DSGs in many makes and the CVT has been affected by driveability problems.

Look for hesitation on takeoff, surging or shuddering on acceleration, any apparent hesitation or incorrect selection of gears.

Mileage matters

Everyone hopes to find a low-km, one-owner car that has been pampered and sparingly driven. The fact is that cars wear more as distances climb — but one that hasn't been driven much can be costly, too.

"Things like batteries, radiators and rubber components such as radiator hoses and cam timing belts all deteriorate," says mechanic Don Evans. "Tyres can also look new or barely worn, but might have exceeded their life span." Brakes can also seize up from lack of use.

Buying options

Auction - Trade prices, no test drive, no comeback

Dealer - Retail prices, cooling-off period (where applicable), warranty, test drive, trade-ins

Private seller - Negotiable prices, test drive, no recourse

Murray's checklist

1) Current roadworthy certificate
2) Record of regular servicing
3) Clean and tidy interior
4) Clean and leak-free engine
5) Even tyre wear
6) Body free of bumps or scrapes
7) No sign of off-road use

What to avoid

2004-09 Volkswagen Golf - Dodgy dual-clutch gearbox sours driving experience.

2010-11 Holden Cruze - Auto gearbox problems widespread, costly to fix.

2010-11 Ford Fiesta - Auto transmission troubles make it a risky proposition.

2004-09 Ford Territory - Prone to rust; front-end ball joints don't last.

2006-09 Holden Commodore VE V6 - Camshaft timing chains cost plenty to replace.

What you can buy with confidence

Toyota Camry - Boring but bulletproof. What else can you say?

Mazda3 - Safe and sound, little goes wrong with them.

Kia Sportage - Lots to like and nothing to be concerned about.

Toyota Corolla - Well built, never lets you down and resale is good.

Hyundai i30 - Rated right up there and ticks all the right boxes.

Do you prefer dealers, auctions or private sellers when buying a used car? Tell us about your experience in the comments below.