Holley # 125-165 Power Valve on 2040-parts.com

Mercedes E 63 AMG S: UK price from £83,740

The E63 AMG S is the extreme version of what is already an extreme car in the E63, with a power boost that takes it from 549bhp to 577bhp – and throws in an extra 60lb/ft of torque for good measure too – and promises real extreme performance. The problem is, getting that power down to the road. In left hand drive markets that’s solved by simply offering the Mercedes 4WD option – 4MATIC – which does a much better job of transferring power to the road than the regular RWD layout.

AC 378 GT Zagato supercar at 2012 Geneva motor show

British sports car specialist AC is back and teaming up with fabled Italian coachbuilder Zagato to create the new AC 378 GT Zagato, the first all-new AC for some time. The company has had an on-off relationship for much of the past decade, with production switched abroad, management changes and a confusing product line-up. But new management has been installed and are hoping to make a fist of AC Cars, one of the world's oldest car brands.

William Clay Ford Sr.'s death: Leaders and sports world react

William Clay Ford Sr., who died on Sunday at the age of 88, served in numerous positions at the Ford Motor Company, including 32 years as chairman of the Design Committee, and became chairman of the Executive Committee in 1978. Comments on the death of Ford, the last surviving grandchild of automotive pioneer Henry Ford and owner of the NFL's Detroit Lions: "The Fords are among Michigan's iconic, founding families, and he was an innovator in the family tradition as well as a strong leader. Like his grandfather, he was passionate about automobiles and the auto industry, the city of Detroit and his family.