Mercedes is claiming that its 2007 CL-Class is the quietest luxury car ever. To do this Mercedes designed the airflow-efficient A-pillars and developed a more rigid bodyshell with reinforced outer surfaces. Mercedes engineers have been making sure that the bodyshell would make as little as wind noise as possible ever since the conceptual phase. Mercedes also came up with a new sealing concept for the doors of the CL.
Source: Leftlane News