The E-class comes with an air of authority. On our last E-class test, we arrived outside our home one night to be greeted by no less than the town's mayor. He was there to welcome Pakistan's ambassador to our neighbour's house, but the sight of a shining black E-class seemingly signalled a dignitary had arrived.
For a moment, uncertainty was writ large across his face: could this person in jeans with a basket of laundry under the arm possibly be her Excellency? The moment passed and the Ferrero Rochers were quickly reboxed.
The experience underlined for us the connotations of executive models bearing the three-pointed star - power and privilege. It's what other car firms would kill for.
This time our test car was the diesel version, a favourite not only of the company exec but the continental taxi driver as well. It's also regarded within the motoring press as the best E-class buy. You begin to understand why when you get behind the wheel - It's all elegance and luxury with a relatively frugal oil-burning engine.
We aim to cater for all-comers in our reviews, but the likelihood of influencing German taxi drivers is slim. Potential purchasers here are going to be largely management or cabinet ministers. For these, the upper-executive choice seems to come down to Mercedes or BMW. The others, like it or not, are also-rans in this race.
Figures back this up: in the first two months of the year, the E-class had 21 per cent of its segment, followed by the 5-series with 15.9 per cent. Other competitors fight it out with 2-3 per cent each.
It's also a market where diesel has made serious in-roads. Oil burners are nothing new to Mercedes, nor to its clientele. Wealthy farmers and builders know from experience the potential of the diesel unit and for decades have not been afraid to match its noisy frugality with the luxury cab and accoutrements of the E-class and its predecessors.
Diesel has come a long way since then, mostly because of common-rail technology. That's what is offered in the 320 CDi, a turbocharged six-cylinder. The problem for Mercedes now is it's being hotly challenged by one of the best diesel engines around - BMW's 3-litre unit.
In like-for-like comparisons the BMW has it in terms of power and torque (though each offer 498 Nm, the BMW offers it at lower revs.) But on the road there's little between the two and the 320 CDi offers up the power so smoothly that it gives the driver an immense confidence to pull away in tricky overtaking situations.
On the motorway it's as smooth a cruiser as you'd expect and that's what most desire. But its back road ability shouldn't be ignored. When combined with this diesel, it offers not only good handling and power but good fun as well. That's not something you expect from such a big car, but weaving through the corners it feels surprisingly well-balanced.
Our previous E-class test car was an E240, whose front seemed too light at higher speeds, so the steering didn't feel as confident.
Here, with the few extra kilos on board mainly at the front, the whole car feels better weighted. When it's about getting instant power response and combining executive class space with the handling of a smaller car, the E-class manages to pull it off.
As for noise and harshness, the engineers haven't been able to disguise its roots when starting from cold, but once warmed up the 3.2-litre unit doesn't disturb cabin tranquillity. BMW may have pipped it here as well, but that won't bother Mercedes buyers, a loyal and growing constituency.
The official combined consumption figure is 40.9 mpg. We managed to get pretty close to it with an average 35.4 mpg in a mix of crawling town traffic and open motorway. In the city we were averaging over 25 mpg.
No Mercedes review would be complete these days without mentioning the quality issue. Once the pinnacle of reliability, respected surveys have recently recorded a fall from grace. Most pundits have an opinion on the reasons, but it seems to be down to the ill-fated takeover, sorry merger, of high-flying Daimler and leaden Chrysler. Many top managers, and some top brains, were removed from the prestigious home ground to stop the haemorrhage of quality and cash at the ailing US firm.
This scenario is supported by the recent decision to bring back Wolfgang Bernhard to take over the reigns at Mercedes from the current incumbent who is retiring. By all accounts Bernhard is a no-nonsense high-flyer who has played the hard-edged role in a good-cop-bad-cop management routine at Chrysler alongside boss Dieter Zetsche.
He won't solve the problems single-handedly, but it's the most promising sign to date that the lapse in the quality ratings is just a blip in its history.
Our car carried the Elegance specification, fit for a Taoiseach. As in exterior design, inside the E-class doesn't court controversy, preferring the more conventional button approach to the likes of the BMW iDrive. Certainly the dash buttons could be better quality and the speedo-meter is only in mph meaning that, come September, either the owners of these €70,000-plus cars will be looking for coloured markers, or they will be attaching calculators to the side of the dashboard.
These matters aside, there's a definite air of importance to the spacious layout. The legroom for front passengers is ample enough for any long-legged politician to stretch out without encroaching on the back-seat passengers.
Best of all was the radio, featuring shortwave bands as standard, allowing us to access our favourite window on the world, the World Service. It's an aural adventure tale featuring reports from the five continents. As you listen in Dublin, you're aware there's someone else straining their ear to pick up the words in Kinshasa, Buenos Aires and Ulan Batur - a truly global community.
It's appropriate to be able to tune in to such a global station in a car that, along with its bigger S-class sibling, is the transport of choice for world leaders from Mongolia to Argentina. Shortwave as standard symbolises in some way the model's global reach. It's the power taxi that carries with it an air of importance and the diesel version is probably our favoured choice on the E-class fleet.
Last week our Competition panel listed the price of the Fiat Idea at 24,495. The correct price is
22,495, as was listed in the Factfile published with the article.