Arias Pistons 12.5:1 Compression 82mm Bore Honda B-series on 2040-parts.com

Alfa Romeo 4C spied in Michigan

During the Detroit auto show in January, Fiat and Chrysler CEO Sergio Marchionne told us -- in his own irreverent way -- that arrival of the long-promised Alfa Romeo 4C would be delayed once again. But as these spy photos show, testing on the sporty coupe continues even as a debut date remains elusive. This isn't the first time we've caught the 4C testing in the States.

60 years of Unimog spawns off-roader concept

Mercedes-Benz is paying tribute to 60 years of Unimog trucks with a mean, green off-roader concept that the company claims stands for future versatility in vehicle design. In a nod to the first Mercedes Unimog--built in 1951 and reinstated with the 2010 product range--the team of Mercedes and Daimler designers gave the 2011 design concept an open cab. They injected the U 5000's off-road capabilities into the equation as well, drawing on the truck's historic design strengths.

BMW's Domagoj Dukec on the 4 Series Convertible [w/Video]

BMW's head of exterior design Domagoj Dukec has explained how the 4 Series Convertible's design sets it apart from the 3 Series in a new video. Dukec says that aside from the fact the 4 Series Convertible is visibly wider than its predecessor with an increased track and wheelbase, its design is unique. While describing the changes to features such as the kidney grille, headlamps and the lines running down the hood, Dukec also compares it to the coupé.