Porter's five force strategy is a framework for making a qualitative evaluation of a firm's strategic position which according to Porter should be used at the industry level, a marketplace in which closely related substitutable products or services are sold. Porter's analytical framework consists of those forces that affect a producer's ability to serve its customers and its profitability. A change in any of these five forces requires a re-assessment of the marketplace. The U.S. Auto Industry U.S. Auto Industry Definition 3.2. U.S. Auto Industry Market Structure 3.3. U.S. Industry Future Outlook Application and Analysis of Porter's Five Forces Strategy to the U.S. auto industry 4.1. Bargaining Power of Buyers 4.2. Bargaining Power of Suppliers 4.3. Competitive Rivalry in the Industry 4.4. Threat of New Entrants 4.5. Threat of Substitutes