correction needed. the 508 is actually based on the 308 chassis which appears to be the primary & common chassis in their new range 308, 3008, 508 etc. The C5 appears to share a common chassis with the 407. Double wish bone front and multi link rear. This is a "costlly and complex" set up and offers very good driving dynamics. Grip gets better (up to a certain point obviously) the harder U can accelerate into a corner. The Alfa 159 is another good example for such a set up. FWD handles better with double wishbone design compared to Macpherson struts, though there are exception like the Golf GTI and Ford Mondeo.