LOOK UNDERNEATH THE CAR

Spread an old blanket on the ground, so you can look under the engine at the pavement. Use a flashlight. If you see oil drips, other oily leaks, or green coolant, it’s not a good sign. If you can find the spot where a car was habitually parked, see if that of the garage floor or driveway is marred with puddles of oil, coolant, or transmission fluid. Check the ground beneath the fuel tank for fuel drips from the fuel-filler tube and gas tank.

Don't be alarmed if some clear water drips from the car on a hot day. It's probably just water condensed from the air conditioner.

Examine the constant-velocity-joint boots behind the front wheels. They are round black rubber bellows at the ends of the axle shafts. If the rubber boots are split and leaking grease, assume that the car has or shortly will have bad C-V joints-another item that's costly to repair.

Feel for any tailpipe residue. If it's black and greasy, it means the car is burning oil. The tail-pipe smudge should be dry and dark gray. Look at me pipes. Some rust is normal. Heavy rust is sometimes normal but could mean that a new exhaust system might be needed soon.

TAKE A TEST DRIVE

If you're still interested in the car, ask to take it for a test drive. Plan to spend at least 20 minutes behind the wheel, to allow enough time to check the engine's cooling system and the car's heater and air conditioner.

Comfort. Make sure the car fits you. Set the seat in a comfortable driving position and attach the safety belt. Make sure that you're at least 10 inches away from the steering wheel and that you can still fully depress all the pedals. Typically, seats fit some bodies better than others, so make sure the seat feels right for you. Make sure that you can reach all the controls without straining, that the controls are easy to use, and that the displays are easy to see.

Steering. With the engine idling before you start your test drive, turn the steering wheel right and left. You should feel almost no play in the wheel before the tires start to turn.

Once under way, the car should respond to the helm quickly and neatly, without lots of steering-wheel motion. At normal speeds, the car should maintain course without constant steering corrections.

If the wheel shakes at highway speed, suspect a problem with wheel balance or the front-end alignment, which is easily fixed, or with the suspension, which may not be. Likewise, if the car constantly drifts to one side, suspect that a tire is underinflated or that there is some suspension problem - something to have a mechanic check.

Engine and transmission. The engine should idle smoothly without surging or sputtering, and accelerate from a standstill without bucking or hesitating. When you accelerate up a hill, you shouldn't hear any pinging or clunking. The car should be able to keep up with highway traffic without endless downshifting.

With an automatic transmission, don't confuse smoothness with slippage. When you accelerate, there should be no appreciable hesitation between the engine's accelera­tion and the car's. If there is, it's an almost sure sign of transmission wear - and a costly fix down the road.

With a manual transmission, the clutch should fully engage well before you take your foot all the way off the pedal. If there isn't at least an inch of play at the top of the pedal's travel, the car may soon need a new clutch.

Brakes. Test the brakes on an empty stretch of road. From a speed of 45 mph, apply the brakes hard. The car should stop straight and quickly, without pulling to one side and without any vibration. The pedal feel should be smooth and linear, and stopping the car shouldn't take a huge effort. If the car has antilock brakes, you should feel them activate with a rapid pulsing underfoot when you push hard on the brake. (It's easier to make the antilock braking system activate on a stretch of wet road.)

Try two or three stops; the car should stop straight and easily each time. Then pull into a safe area, stop, and step firmly on the brake pedal for 30 seconds. If the pedal feels spongy or sinks to the floor, there may be a leak in the brake system.

Look, listen, feel. At a steady speed on a smooth road, note any vibrations. You shouldn't feel shuddering through the steering wheel, nor should the dashboard shake or the image in your mirrors quiver noticeably.

Drive at 30 mph or so on a bumpy road. You want a compliant, well-controlled, quiet ride. If the car bounces and hops a lot on routine bumps and ruts, it may mean the car has suspension problems or the car's chassis wasn't designed well in the first place. Listen, too, for rattles and squeaks-they're annoying to live with and often difficult to track down and fix.