Take your time and look at the car in daylight. Check the body panels for uneven gaps or mismatched paint, the tyres for even wear, and the engine bay for leaks. Ask for the inspection report and compare it with what you see.
Start the car cold, listen for unusual noises, and test every switch, window and light. Take a test drive on both city roads and open roads if you can.
Finally, check that the documents match the car. If anything is unclear, ask before you decide.