The CLS has split opinions: some love its curved, elongated features, with the high waistline contrasting with a low profile roofline; others claim a similarity to a banana and a rump overhang that looks like it’s melting.

One thing’s for sure, Mercedes’ new four-door coupé stirred a huge amount of attention from other motorists, with several people overtaking just so they could capture a picture on their mobile phones. Dealers need to convert this interest into sales. Mercedes expects to sell 2,500 models this year (so far it’s on 1,300), and 4,000 in 2006.

In addition to the coupé’s distinctive appearance (by the way, we think the body style is terrific, especially viewed from the front three-quarters, with almost every angle offering something fresh and unique to look at), the CLS should help to restore Mercedes’ reputation for top quality build.

The stylish interior is stitched leather and wood panelling with the usual Mercedes dashboard layout – a steadfast refusal to follow BMW and Audi down the iDrive/MMI central console route.

Four people are seated in comfort with a surprising amount of legroom and reasonable headroom considering the sloping roof. One problem, however, is the rear doors. They are a bit too small, which means the gap is uncomfortably tight for larger people to get in and out. That aside, the CLS has an ample boot, making it highly practical.

Buyers choose from three petrol engines and, from this month, a 3.0-litre diesel, the £42,225 CLS320CDi. This will account for two-thirds of sales next year, while the £43,115 3.5-litre CLS350, a newly developed V6 engine, will take 20%. The balance will be split between the £52,115 5.0-litre V8 CLS500 and range-topping 55 AMG, priced £70,565.

Of the petrol options, the CLS350 is our top choice. Only marginally slower in a straight-line sprint to 62mph than the 500 (7secs against 6.1secs), it offers a punchy mid range and smooth acceleration thanks to torque of 258lb ft peaking at 2,400rpm. Fuel efficiency is reasonable, 28mpg combined, while CO2 emissions at 241g/km is much in line with its main rivals.

However, the figures suggest our overall favourite will be the new diesel. Promising an identical sprint time of 7secs, it also offers a more economic 37.2mpg and tax-friendly 202g/km CO2 emissions.

Although Mercedes has used a combination of sheet steel and aluminium in the bodyshell to keep weight down, the CLS still feels like a big car on B-roads. Airmatic air suspension, standard fit on the 500, improves performance and gives the car confident handling. On the downside, the brakes are a bit sharp, while the gearbox can be jerky accelerating at lower revs. And we couldn’t tell much difference between the comfort/sport settings.

Strength
Looks, build quality, ride

Weakness
Looks, gearbox jerky at times, small rear doors

Opportunity
New niche for Merc dealers

Threat
Yet another new niche – is Merc being too clever?

The USP
Premium four-door, four-seat coupé

Price: £43,115-70,565
Transmission: Seven-speed auto; five speed auto (AMG only)
Performance: 3.5-litre 0-62mph: 7sec; 5.0-litre 6.1sec; 5.5-litre 4.7sec; 3.0-litre CDi 7sec
Top speed: all limited to 155mph (CDi:153mph)
Efficiency: 3.5-litre fuel 28mpg, CO2 241g/km; 5.0-litre 25mpg, 268g/km; 5.5-litre 21mpg, 326g/km; 3.0CDi 37.2mpg, 202g/km
CAP RV 3yr/30k: 3.5-litre: £20,625 (48%)
Rivals: Maserati Quattroporte, BMW 5-series, Audi A6, Jaguar S-type