Dear Doctor: I own a 2006 Ford Focus that I wanted to replace the air filter. To my surprise the only place to buy it was the Ford dealer at a cost of almost $600! This is crazy. What are your thoughts? Melvin
Dear Melvin: You are not crazy. The air filter you are referring to is called an air box that is located between the left front bumper and wheel well molding. It is a complete large assembly. The recommended replacement is 100,000 miles. There are some performance aftermarket air filter assemblies that cost less that are serviceable for your vehicle. You will need to check around in your area.