Buying a second hand car is not as difficult as it may seem. That is if you get the basics right!
First off go see the car when you are relatively free. You have to spend as much time possible with the car.
Inspect the car externally. Look out for signs of accidents. A tell tale sign is paint mis match. Also look out for rust. Though pretty rare on modern cars, still can happen. Especially look for rust under wheel arches, door sills, inside engine compartment, floorboard.
Now take a look at the interiors. It should be in decent shape. Especially the seats.
Go for a drive. Drive as slow as possible and hear for any strange noises. Now accelerate and see if the car pulls away smoothly or struggles to pick up. Check for any wobbling or vibrations. Check steering. There should be no noise. Check the AC and other electricals. They should all be fine. Brake. They should be smooth and progressive. The vehicle should not pull to a side.
Now get down and take a look under the bonnet. If its dirty, then rest assured thats its seeing daylight after a long time! Check the fluid levels. This too will tell you how well the car has been cared for. Also look out for rust, especially near the battery. Listen for strange noises.
Check the tires and suspension.
Now if you are happy, check the vehicle service history. This will tell you how well the car has been looked after.
Check all other legal documents and see that they are in order.
If all is well, then strike a deal!