And a showroom performance that saw it outsell the Renault Laguna last month proves that the car criticised for having unimpressive looks is fast winning fleet friends.
The fact that this alternative to the large family saloon is getting second looks from some of Britain's most discerning motorists comes as no surprise at Fleet News - the Exclusive 2.2HDi became a favourite a long time before it completed its six-month stint on our long term test fleet.
After thousands of miles of armchair comfort, relaxed performance and excellent economy, we can well appreciate why the new model has got off to a quicker sales start than the Xsara Picasso, now the UK's best-selling compact MPV. The registration total may pale in comparison with the figures for the Mondeo and Passat, but it is a significant achievement for the French manufacturer.
Designed to start a new styling trend for the brand, this model is only slightly bigger than the Xantia. But clever packaging has created an interior that provides a remarkable amount of stretching space.
Backed by the latest version of a suspension system that soaks up the bumps with aplomb, the roominess is a big factor in making light work of long stints at the wheel.
While high rear end styling makes the C5 more difficult to park than some of its rivals, a huge windscreen and relatively high driving position give the wide field of vision that helps progress on motorways.
As most of the car's time with us has been spent on major routes, we've had maximum benefit from another strong feature - the company's latest common rail HDi turbodiesel engine, which blends a stout torque output with a meagre thirst for fuel.
Fitted with the PSA particle filter system, the 2.2-litre unit banishes the sooty exhaust and boasts an emissions level that matches its overall refinement.