Gabriel Shenhar, senior auto test engineer at Consumer Reports, says expect to replace tires, brakes and other parts of the car subject to everyday wear and tear.

Parts such as alternators, thermostats and water pumps are replaceable but shouldn't break down regularly. When you start to have problems with parts such as these, don't necessarily get rid of your car but be aware that your car might be close to pulling your finances into a bottomless pit.

"It's always ... going to be more expensive ultimately to lease or buy a new car or even a late-model used car," he says. "But you're also buying yourself more peace of mind."

Of course, personal finances and willingness to deal with problems as they arise play a role in your decision.

After an auto accident, the damage you don't see is sometimes the most expensive and can cause an insurance company to total your car.

Items not visible to the eye, such as electronic relays or transmission mounts, can make a car a complete loss, says Ozene Cumberland of Ozene Cumberland Body Shop in Brandon, Miss.

A deployed air bag, whose replacement cost could range from $500 to $1,100 in many cases, increases the chance a car will be totaled because other problems might be discovered upon closer inspection, says Marilyn Bolden, co-owner of Bolden Body Shop in Jackson, Miss.

Insurance companies often opt to total a vehicle when damage reaches 65 percent to 75 percent of its retail value, Cumberland says.

But don't get rid of your old car just yet.

Like it? Fix it.

"A whole lot depends on if they like the car or not," says Nelson Trabue, general manager of Import Auto Maintenance in Nashville, Tenn. "If they like the car, it almost always pays to fix it."