Thank the Lord for cars like the elegant CL coupé. Nothing comes close to its technological tour de force - a fine wine in a cellar full of Tesco specials. It's a rare beast (only 265 were sold in Britain in 2005) and production of the current model is due to end soon in advance of the arrival of its 2007 model-year replacement. The "new" CL will be unveiled in Germany in June 2006 and go on sale later this year, but for now the seven-year old C215 is a unique reminder that not every supercar has to be an outrageously-styled hedonist to be the best.My CL 500 test car is the baby of the range, a mere £73,700 four-seat carriage with Mercedes' lusty five-litre V8 under the bonnet transferring its relatively modest 306bhp and 339lb/ft of torque to the rear wheels through the cracking 7G-Tronic seven-speed automatic. That adds up to a respectable 6.3 second sprint to 62mph, impressive mid-range overtaking bursts and a top whack limited to 155mph.It's the entry-level CL in a family of four which includes the sewing-machine smooth 500bhp CL 600 V12 (£98,125), the sharp-suited 500bhp CL 55 AMG (£98,795) and the manic 604bhp CL 65 AMG (£146,000). They are all fine cars - but by far the best buy is the CL 500.In a world where excess is celebrated and an "entry-level" mentality marks down cars like the CL 500, it is a classic case of less is more. The 500 delivers everything you need from a comfortable continent-crossing four-seat coupé: rapid performance, luxurious trim, stunning handling and subtle superiority.I was impressed, but £73,700 is still too much to pay for a car like this. The CL 500 makes very little sense as a new buy unless you are a Lottery winner, but in the years ahead it will become a used luxury icon as it sheds thousands of pounds in value without losing any of its quality, performance or appeal. Buy a three-year old CL 500 with average mileage today and you'll pay well under £30,000. Now that's economic sense, and you still get a stunning, hard-wearing coupé.Everything about this car is limousine-sized. Nose to tail it occupies five metres, and it's over two metres wide between door mirrors. Seating is superb, soft leather-trimmed with armchair-dimensioned heated and electrically-adjusted front seats, and sufficient room in the back to deliver saloon car comfort and space. The boot is huge for a coupé with 450 litres available and a low-silled electric soft-close lid.The massive doors are nearly 1.5 metres long and mounted on clever cantilever hinges which move the entire panel forward and out to maximise entry space. Closing these huge barn doors could present a problem in a high wind if not for Mercedes' attention to detail with powerful springs to check movement and soft-close electric power to ease them snugly shut.When the current model appeared in 1999 I was unconvinced by its styling. There is still something uncomfortably out of sync aft of the C-pillar - the rear side panels are too long and give the car an elongated profile which robs its low roof line of ultimate elegance. Then again, that's where the big boot comes from.On the road the CL's sheer bulk and nearly 1.9-tonne kerb weight do nothing to blunt driving satisfaction. Leviathan it may be, but it feels lithe. Once you've set the Active Body Control (ABC) from the soft Convenience mode to beautifully controlled Sports the CL can be hustled around with speed and accuracy. It's not a car that lends itself to blistering cross-country drives - it's just too refined, too laid back and too well-mannered. An elegant lady with breeding should never be rushed.But if you open it up you won't be disappointed. Body control is remarkable. Fast, ill-surfaced corners won't upset this monster's line, the Servotronic steering feels a little dead at speed but maintains great feel and excellent feedback, while the industry-leading 7G-Tronic seven-speeder in Sport setting keeps the revs up and the power down. The only limitations a sporting driver will experience with the CL relate to its size.Equipment levels are excellent - as I'd expect for more than £73,700. But Mercedes can still surprise with its options list. My test car's final on-the-road cost was £78,405 thanks to an unnecessary set of special 18" alloys which cost £1300; questionable Keyless-go at £880; indulgent TV tuner for £735; interestingly-ventilated Comfort front seats for £625; pricey wood and leather steering wheel for £460; essential phone pre-wiring (which ought to be standard) for £430; and pointless Linguatronic voice activation for £320.Personally I could do without all of the above, but especially the Linguatronic which failed to recognise anything I, eventually, shouted at it. An automotive frippery which is not even worthy of an Innovations catalogue.Under-rated, low-volume and limited-demand sum up the CL 500, but don't be fooled into thinking it's a non-event. It is a diamond in a box of look-alike glass beads. It's not hip, never brash and oozes conservatism with a small "c", but it is deeply satisfying and has an elegant simplicity of form which will allow it to age gracefully. Engine 4966cc, 8 cylinders Power 306bhp Transmission 7-speed automatic Fuel/CO2 24.8mpg / 270g/km Acceleration 0-62mph: 6.3 seconds Top speed 155mph Price £73,700 Details correct at publication date