01: First I began by opening up a image of a car and then I created a plane. I Basically traced the image using the plane by adjusting the Vertex for example extruding and scaling them to fit the car.
02: The next step was to mirror half of the car which I have already created by using the mirror modifier and I then smoothed out the texture by using another modifier called 'subdivision surface'. This made the car bumps a lot more smooth.
03: To create the headlights and the detail within the car windows I went into edit mode and selected the faces of the windows etc. Once selected a extruded and scaled several times to get my desired look.
Final look
