Arctic Cat High Flow Intake Kit on 2040-parts.com

Porsche celebrates 50 years of the 911 at Pebble Beach

Seven generations across 50 years; nobody has ever matched what Porsche has done with the 911. What started out as the Porsche 901 quickly became the 911 – and wouldn’t take long to become a legend. As one of the most accomplished road-going supercars ever created, it's easy to see why the 911 is also a consummate champion in the motorsport arena – and to celebrate that fact, at Pebble Beach 2013 there was a huge array of road and race 911s, courtesy of Porsche itself along with a stack of private owners.Click through the gallery to see our pick of these great cars...

Shelby American adds SCCA-ready version to the GT350 Mustang mix

Enthusiasts who want to take the new GT350 Mustang racing in Sports Car Club of America events are getting some help from Shelby American. The Las Vegas-based company, which upfits the 2011 Ford Mustang GT to create the GT350 Mustang, will add a normally aspirated version to the lineup. When Shelby American first announced the GT350 program in January, it centered on a supercharged version of Ford's new 5.0-liter V8 that would make about 500 hp.

Audi A9 coupe/cabriolet planned for 2014

To achieve its goal of becoming the world's leading premium car maker by 2015, Audi continues to pull out all the stops. And while the range is stretching down with the A1 and imminent A2 superminis, Ingolstadt is also eyeing a move upmarket - with a proposed new A9. A new Audi A9?