The Audi A4 has been the German automaker’s best-selling model for 39 years running with over 10 million individual examples sold, so any sort of major update to the machine is a big deal in Ingolstadt. For the 2013 model year, Audi has bestowed its A4 with revised sheetmetal and powertrains in order to keep it at the forefront of the entry-level luxury car arena… which is especially important with a new BMW 3 Series on its way. Funk Flex