Sometimes, to draw a picture, the easiest way is to take an existing drawing and trace it. You can use tracing paper, a light screen, or a digital drawing tool. This method works well for machines and buildings.
To draw a car, you need a picture with a car. If you know me, then you definitely know which car I'll choose :-)
First, you need to draw the wheels. Next - trace the outer contour with a thick, confident line. Then with a thinner line - the details and edges. After that, remove the reference image and add the missing details, shadows, and color.
Sounds simple :-)