Choose from two turbodiesels: a 171bhp 2.2-litre four-cylinder or a 2.7-litre turbodiesel V6 with 205 bhp. Both come with six-speed automatic gearboxes. The V6 is quick, flexible and has reasonable running costs, but the 2.2 is our pick because it has more than enough performance and it's cheaper to buy and run.

The C6's active suspension helps keep things level regardless of the load the car is carrying. The emphasis is on comfort, so don't expect the last word in body control, and with ultra-direct, ultra-light steering, it all takes some getting used to. The ride around town can be lumpy and noisy, but on fast main roads the C6 is superb.

The intrusion of road noise on poor surfaces comes as a surprise and a disappointment, especially as in other respects the C6 is an extremely refined car. The automatic gearshifts are smooth and the engines are cultured and quiet. Wind noise is almost non-existent at UK speed limits.

Prices start at more than £28,000 and extend to well over £35,000 – for a Citroën. Running costs are relatively high, too. Resale values and the approach of Citroën's discount-driven dealers are also major concerns. We would be very wary, indeed.

Not in the same league as Audi for fit and finish, but a big step forward for Citroën. There are some nice textures and materials in the cabin, and a few delightful touches, such as the vertically siding door pocket lids. The engines are proven, but we'll be interested to see how the complex suspension stands the test of time and mileage.

A maximum five stars in Euro NCAP crash tests for occupant protection and four for pedestrian safety (a first anywhere) – the C6, complete with nine airbags, looks after those inside and out. Stability control is standard, while options include a lane departure warning system. Security is unproven, but the essentials are present.

Plenty of adjustment for the steering wheel and seat ensure it's possible for almost anyone to find an ideal driving position. However, no matter who you are, you'll have problems judging the corners of the car while parking, because of its dramatic shape – thank heaven for parking sensors. The control layout is confusing, too.

The C6 is the kind of car that will be ferrying French Cabinet ministers around Paris, so rear-seat space is understandably plentiful, although really tall passengers might have a bit of a problem with headroom due to the swooping roofline. Luggage space is not a strong point, either.

The C6 is packed with all the creature comforts you'd expect of a car with this kind of price tag. Many things aren't easy to get to grips with, though – the elaborate electric seat adjusters for starters – and there are omissions. Items such as keyless entry and starting, offered by German and Japanese exec rivals, aren't even optional.