Look under the car up and down its entire length. Any fluids dripping to the street? Look around the area for dark patches on the ground.

 
• Study the fluids. Oil or manual transmission fluid is black, while automatic transmission and power steering fluid is red.

   

• Antifreeze or coolant are thin, watery liquids, usually green but sometimes red.

   

• Gas and water are clear and mostly colorless. It's not unusual for a used car to leak a bit of oil from the engine block or some water after running the air conditioner, but have your mechanic examine the source of any leaks.

   

• Take a look at the tires--including the spare, which is often the most worn. A tread that's uneven to one side is a sign of poor alignment or balance. A lack of tread on the outside or inside of the tire usually means over or underinflation.