THE ‘5’ in C5 can mean more than just which Citroen model this is.

Five can refer to the vehicle’s ‘5 Series’ sizing, if not positioning – but the fact that the number is in between one and ten neatly places it right in the middle of Citroen’s model range.

Unkind people might also utter that the original (2001—2008) C5 only merited a ‘5’ out of 10 in its mid-sized family car class using this logic suggests the Mazda6 should have been called the Mazda9!

However, ‘C5’ can no longer stand for ‘5-dr hatch’ as it could have with the previous version because Citroen has abandoned the lift-back for a four-door three-box boot… Cancel-5 perhaps?

And now the arrival of this aforementioned second-generation C5 means that it is the fifth instalment in a colourful and at times superb lineage of mid-sized Citroens.

These began with the astonishingly complex GS of 1970 (the model that ultimately helped place the bankrupt icon right into the arms of arch-rival Peugeot in 1976), and went on to include the boxy BX of ’82 and 1993’s sharp Xantia.

Now all five mid-sized Citroens remained near-enough faithful to the marque’s philosophy of advancement through technology, which manifest itself most obviously though hydropneumatic suspension and acute aerodynamic design, among a variety of other smaller innovations.

But there is something different about the latest C5 – something altogether more serious.

Citroen in the UK alludes to this in no uncertain terms through a cheeky marketing campaign, calling the C5 ‘Unmistakably German’ in an ad complete with blondes, bratwurst, lederhosen, autobahns, Wagner’s Ride of the Valkyries and even the Verdienstorden vom Deutschen Adler (Eagle coat of arms), while a tiny disclaimer in the end pops up to say ‘Made in France’ or just ‘west of Alsace’ (on the German/French border).

Even the new C5’s humour is German.

Sacre bleu we hear you Francophiles. Well... the DS was sculptured by an Italian who would have grown up during B Mussolini’s Fascist regime!

Yet while we are sure that nobody is really going to confuse this with an auto from the Fatherland, the C5 is aggressively sculptured in a Bangle-era BMW way where the old one seemed soft and flabby.

The very antithesis to the timeless beauty of the lithe Xantia or the futuristic BX, the Citroen’s handsome design is very now, gelling together forcefully and with plenty of presence. Perhaps it is a bit like the rugged Robert Redford to a young Paul Newman.

But will the C5 age as well?

Further taking the Teutonic route is the interior, as it isn’t flaky or flimsy or fruity in that glorious old way of French cars past. Believe us, it is a solid and squeak-free place to be, as well as an undeniably opulent one.

But whether we would call it an unqualified success aesthetically is debatable, because further inspection reveals a hodgepodge of bitsy Peugeot 407-like switchgear (especially around the fussy centre console) and the smaller Citroen C4.

Our Exclusive level test car’s dashboard did the C5 no favours by being unrelentingly beige, as it appeared to cheapen some of the plastic trim. Hints of Deutschland E-class taxi, you say?

Our advice is to be daring or different with the choice of trim and/or material options, and you might end up with something striking and classy. You Tube ‘Citroen C5’ and watch how lovely the promotional film vehicles’ cabins are. That’s when you really believe the Unmistakably German hype.

Still, even in our bordello-beige C5, there are many smartly modern materials employed among it all, such as the grained dash-top and metallic inserts, to lift the interior up to a hitherto unknown level for a modern Citroen.

Indeed, the environment directly ahead of the driver is the most impressive area to behold, since the dashboard’s cool white analogue markings, offset by orange digital graphics, looks totally contemporary yet is somehow classically elegant in design and execution.

Then there’s the steering wheel boss - fixed as in the C4 and complete with simple cruise control and speed-limiter functions on one side, remote audio switches on the other and a handy pair of thumb scrollers for the very (maybe too?) comprehensive trip computer functions.

The wheel is a pleasure to use regardless of its boss’ positioning because it is perfectly sized and lovely to hold.

Ventilation is ample, the clap-hand windscreen wipers cover a sufficient area of glass, the electronic park brake can be deactivated without having to fiddle around with the rather slow-to-react lever and the small glovebox is augmented by a deep centre console, door-mounted bins and a hidden dash compartment.

Yes, the vast array of buttons can overwhelm novices, but in time familiarity will definitely make everything much easier to find in a hurry.

Furthermore, the ideal driving position will take no time to achieve, and not only because the steering wheel tilts and telescopes and the seat lifts and slides to suit.

Citroen has fitted German-style front seatbacks that tilt the upper half for added comfort and support, further increasing the C5’s overall appeal and adding that elusive air of luxury inside.

Anti-whiplash head restraints are also fitted, but these are not as effective as the superb items fitted to the C5’s homegrown rival, the unashamedly French Laguna by Renault.

As is very obvious from the photographs, the Citroen is quite a big car and there’s plenty of room for four adults, even with the front seats set halfway back.

Occupants back there sink into deep bucket seats and are presented with vent outlets on either pillar, a folding centre armrest (with boot access for long narrow objects) a small storage compartment and a pullout set of cupholders, and a feeling of airiness as a result of the small D-pillar window.

Our car featured side and rear sun blinds for that princess-in-exile feel, that – along with nice ambient lighting dotted around the cabin – really goes a long way in fulfilling Citroen’s luxury car aspirations.

There hasn’t been a mid-sized Citroen four-door sedan sold in Australia since the demise of the GS in the late 1970s, and the latest C5 is a better car for having a generously sized 439-litre boot to swallow all sorts of flotsam and jetsam. The split-fold rear seats are a bonus too – you don’t always have this feature in large sedans (VE/WM Holden, anyone?).

We should mention some of the high-tech toys the C5 Exclusive is fitted with, including an excellent set of cornering lights that – in classic DS style – see round corners for you in the dark a massaging driver’s seat to keep the fear of DVT at bay and mood lighting that creates a homely and inviting ambience.

On the other hand, we felt (literally) that the front-seat warmers are not hot enough on the maximum setting – and this came as a surprise because we expected the excellent climate-control system to not be as cold as it is and the optional Bluetooth ‘connectivity’ kept falling out in and around central Melbourne.

Overall, however, the Exclusive’s long list of standard items – that also include nine airbags, attractive 18-inch alloy wheels, a good stereo system with MP3 capabilities and a cruise control system with an excellent speed-limiter function (why don’t Australian cars have this?) - certainly added to the sense that the C5 is a well-priced prestige alternative.

But the best playthings in this car are not toys at all.

The C5 Exclusive V6 HDi has a 2.7-litre twin-turbo diesel with a particulate filter, to deliver the sort of easy, laid-back performance you might expect from a big V8 – and with virtually no discernible diesel clutter or din.

With 440Nm of torque at your disposal from 1900rpm, the V6 HDi whisks you away after that initial split-second lag period that all diesels have, and then the forward thrust just keeps on coming on like an avalanche.

Overtaking takes no time at all doubling your speed from 60km/h is achieved in about as much time as it takes to think about doing so and cruising beyond that is ultra-relaxing and incredibly intuitive in this slingshot of a car.

And even the six-speed automatic gearbox is in tune with proceedings (which hasn’t always been the case for auto Citroens), shifting ultra-smoothly while dealing all that drive to the wheels ahead of you as cleanly as you could hope for such a powerful front-driver.

We averaged around 13L/100km after much hard city and urban driving, but Citroen claims an 8.5L/100km result, which is possible over the combined cycle.

Then there is the complex hydropneumatic suspension, which does an outstanding job of putting as much distance between the C5 occupants and outside noise, vibration, bump and harshness as it possibly can, imbuing all with the luxury of isolation.

This latest set-up, known as the computer-controlled Hydractive III-Plus version of a 55-year-old system, available in Normal or Sport modes, features a set of rear suspension stiffness accumulators to alter the height and firmness of the damping properties in order to deliver both comfort and car control.

On rough roads it automatically rises to give better clearance, and lowers at high speed for greater stability and improved aerodynamics.

As with all hydropneumatic Citroens, the driver can alter the height of the car, in four ways with the C5, to aid clearance or loading/unloading. The company says it is maintenance-free for five years or 200,000km.

You have to go right up to Mercedes S-class or Lexus LS levels of plutocrat motoring to be this well insulated, and this – more than any gadget or gizmo – makes the C5 feel like a premium product.

If you can feel a ‘but’ coming on, you’re right… but it is a qualified one.

Don’t expect German-car levels of body control or steering feedback in the C5. It simply is not the sort of car to hurry along tight corners on a mountain pass, even in the suspension’s tauter-feeling (but not really worse-riding) Sport mode.

Dynamically speaking, what the Citroen does deliver besides a plush and cosseting ride is smooth and accurate steering, loads of grip from both the front and rear tyres to keep you stuck to the road, and a generally flowing attitude - instead of sharp, instantaneous responses from the steering.

You can’t escape the laws of French physics: the front-wheel drive C5 will understeer the Sport mode, while quelling some bodyroll and creating an easier vehicle to throw around a corner, doesn't turn it into a BMW or even a Ford.

And Citroen has set the electronic driving aid nannies into high alert the ESP stability control switches itself back on at about 30km/h no matter what.

We believe that the overwhelming majority of potential C5 buyers will be happy with the car’s driving dynamics and we applaud Citroen for not falling into the trap that many others have – including Renault’s latest Laguna – in throwing away ride comfort in their (often unsuccessful) quest for BMW-like stiffness and handling.

And we are mightily impressed with the way rougher and unmade roads are dealt with. This car simply floats over these, cushioning the driver while feeling immune to skittishness. Control is the key here.

So has Citroen achieved its goal of creating a German-style French luxury car – or is it a French-style German luxury car?

Either way, we believe the latest C5 is – in many ways – the most complete Citroen sold in Australia in generations, as it majors strongly in almost every department with little compromise in the areas where it does not.

So, far from being a middling five-out-of-ten, we reckon that the 2009 C5 V6 HDi Exclusive sedan is closer to an eight.