While there are a lot of people modeling cars in 3D, there are probably a high percentage of them who are not familiar with those who are doing automotive surfacing (using precise NURBS modeling packages) and work with high precision (for actual manufacturing purposes). This tutorial by Ali Ismail gives a glimpse into that world, and will help you if not only more appreciate the world of automotive surfacing/styling, but produce more accurate-looking rendered results for your design models (cars, boats, industrial-design objects, etc.).
This tutorial examines the creation of polygonal meshes with high quality curvature to produce better reflections. Its geared towards artists who have experience in modeling complex hard surfaces such as cars but are looking to have a better grasp on the subject. Using the example of a car body the same principles can be applied to any reflective object whether its a boat, a futuristic concept train or a sophisticated water faucet.
While this is a car modeling tutorial it will not go into any details of the basic process of creating the mesh, specific tools or matching the reference proportions which I feel are better suited for a general modeling or hard surface modeling tutorial and one important thing to be noted is that the level of quality that this tutorial deals with relates to rendering an object with continuous reflection streaks across it. If all what you need is something reflecting an HDR sky environment and you don't mind some reflection distortions that the untrained eye won't catch then this is not for you.
A big reason for creating this tutorial was another tutorial that I have created many years ago when I was starting out my way in 3D graphics and has still been circulating to this day (Making of Mercedes S600 (PDF 7.0MB)). I felt that a follow up is necessary to go into the depths of understanding the intricacies of automotive modeling and laying out the basic principles which distinguishes it from any other type of 3D modeling.