This sports car model I made when I was at the beginning of my modeling career. I have made many mistakes in the modeling process. Some have corrected and some not. Finally, this model is significantly different from the sports car that was used as a prominent example.
The first thing, I did a search on the Internet for blueprints. When I found the blueprints for the side view, front view, top and back views, and I put them in my program for 3d modeling (3ds Max, etc..). Each blueprint I put in a special plane and they served as a reference for my model. Previously, if the blueprints cars do not have equal corresponding dimensions need to be edited in one of the photo editing programs (Photoshop, etc.).. Thus, the length of the car on each blueprint must be the same, width and height too.
When the reference blueprints are set, I began the process of modeling in the way that I first drew a small plain, convert it to an editable poly, so I copied edges and periodically adjusted vertex according to the blueprints.
First I modeled the right side of sports car. When it was fully modeled I just used the Mirror command (Copy) and weld vertex.