Check the car thoroughly...

Walk around the car, looking along its length and check for ill-fitting, mis-matched, odd-colored or rippled body panels which could indicate accident damage. If you're unsure, reject the car. Look carefully for over sprayed paint and bodywork, on the rubber around the windows and inside the petrol flap and for thin paint cover on panel edges. Only severe neglect or serious accident damage to a car under five years old would warrant a total respray.

Squat down a few yards in front of the car and make sure the wheels are properly aligned. If there's any 'crabbing' i.e.. if the front and rear wheels appear to be out of square, then the car could have sustained serious damage to its chassis and body shell. Uneven and irregular wear to the tyres can also be an indication of misalignment. If you suspect anything, reject the car. Uneven wear to the front tyres could mean that the steering is out of alignment, or worse.