When test driving the vehicle take note of sounds when turning and going over humps on the road. Look out the rearview mirror to see if the vehicles are releasing smoke. Does the vehicle drive smoothly and do the Brakes feel sturdy when depressing the pedal? Ensure turn signals and wipers work, Make sure windows and windscreens aren't chipped or cracked, Try and take full turns, both to the left and right, to listen for any noises, Feel that the bite of the clutch holds and go through all the gears, including reverse, And always be prepared to say NO and walk away should you not be satisfied.