If you are looking to buy a 4-door saloon, then what exactly do you need to check? One thing remains constant in all types of vehicles and that is to check the condition of the engine. Whether it has been oiled well or not. It is imperative when you buy used cars for sale to check for the vital components. Including the brakes, suspension, transmission and the condition of the interior and exterior. However, if the car is approved by a professional then you can be at ease regarding the performance. What do you think?