Everybody wants a reliable car. For many car buyers, reliability is the most important factor, as evidenced by the perennial sales leadership of dull-but-reliable cars like the Toyota (NYSE: TM) Camry and Honda (NYSE: HMC) Accord.  

Most cars these days are pretty reliable. Whether you buy newor lightly used, nearly all cars today are more reliable than the Camrys and Accords of 15 or 20 years ago. Almost all automakers who sell their wares in the U.S. have made huge strides in reliability scores, thanks to advances in engineering and assembly technology -- and to the competitive pressures brought about by America's focus on those little circles in Consumer Reports.

But no matter how well your car does in Consumer Reports' surveys, if you plan to keep it for a long time (and you should), how you take care of it will have a big impact on its long-term reliability. Fortunately, taking proper care of a modern car is a pretty simple exercise.

The keys to long life
In the old days, cars needed fiddling with on a regular basis. Mechanical ignition systems needed frequent adjustment, spark plugs didn't last that long, and engine oils degraded quickly. While spark plugs and oils are a lot better (and mechanical ignitions have gone the way of the dodo), cars aren't yet maintenance-free items -- and failing to do the maintenance they require can have expensive consequences.

Here are the must-dos for a happy and long automotive existence:

  • Change the oil. Regular oil changes are the key to long engine life. But how regular is often enough? Whatever oil-change vendors like Midas (NYSE: MDS) say, the correct answer is the one in your car's owner's manual. Period. If you've misplaced your owner's manual, stop by your dealer and get a new copy -- they're not expensive. Or search the Web for the service interval information for your car, but don't take anything you find as gospel unless it's on the manufacturer's official website.
  • Get scheduled maintenance done on schedule. The owner's manual will also tell you when the car needs to go to a mechanic for coolant changes, a new timing belt, etc. While the car is under warranty, have these services done at the dealership. But after the warranty expires, find a trustworthy local mechanic to do the work. Independent garages can access technical information online on most vehicles, and good independent mechanics often do better work than an average dealer service center -- and often charge less, too.
  • Keep it clean and sheltered. Keeping your car looking nice improves its resale value, helps you stay motivated to maintain it, and helps you see rust spots and other blemishes early, before they metastasize into major problems. If you have a garage, clean out those old bikes and use it. If you don't, park out of direct sunlight if you can -- sunlight does lots of damage to paint and interior fabrics over time.
  • Check odd noises and vibrations right away.  That grating sound from the engine, that clicking from near the wheels when you turn, the screeching when you brake -- these sounds are your car asking for attention. Ignoring them turns little problems into big expensive ones over time -- or worse, into safety issues.

On that last point, a personal note: I have a close friend who ignored a clunking sound in her minivan's front end for weeks. She was seriously injured after spinning off the road and hitting a tree when "something seemed to break" in the steering mechanism.

We never did figure out what happened, but a broken tie rod end -- which might have made that clunking sound as it loosened -- is the chief suspect. After two years she's still rehabbing the ankle she shattered, and she may never be completely pain-free.

Keep your car maintained and pay attention to those funny noises, OK?

Fool contributor John Rosevear doesn't own any stock mentioned above. The Motley Fool's disclosure policy once ignored a funny vibration while vacationing in San Francisco. Boy, was it surprised when the freeway overpass fell down.