Renault has been making coupé-cabriolet versions of the Megane since 2003, and I venture to suggest that not all of them have looked particularly elegant (a charge which, in fairness, could be made of other open-topped cars based on conventional hatchbacks). The current example is different. Its shape is smooth but purposeful, with every part of the design flowing into the next part, and Renault has even managed to disguise the fact the car has what might be described in some circles as a lot of "junk in the trunk".The copiousness of the rear end is unavoidable, because that's where the roof goes when it's folded away, a process which takes 21 seconds and requires you simply to press a button and keep it pressed until the whirring stops. It's quite a roof, too, being composed almost entirely of glass. The idea behind that is to give an open-air impression even when you're not actually in the open air, and I can see how that would be welcomed by people who like that sort of thing. (If, like me, you don't, there's a blind which removes the effect almost entirely.)As well as the large butt, there are a couple more inevitable consequences of going down the coupé-cabriolet route. One is that luggage space is severely compromised when the roof is stowed away - the official figure is 211 litres, which is 23 less than you get in the equivalent Ford Focus.The other is that there is almost no room at all for rear-seat passengers. It was pointed out to me that the current Megane CC provides more of this than previous ones did, but it is still true to say that when the driver's seat is set up for me - a six foot three person - there is barely enough space behind it to permit the dropping of a pound coin. Then again, when did you ever see more than two people in a car like this?The engine in the car reviewed here is the 130bhp 1.9-litre dCi turbo diesel, and if you know your Megane CCs you'll realise immediately that this means it also has to be in the Dynamique TomTom specification. Among other things, this includes 17" alloy wheels and a Carminat TomTom satellite navigation system which, oddly enough, is an optional extra on the more expensive GT. GTs are not directly comparable in any case because they have more powerful engines, but for the record their standard equipment includes 18" alloys, a leather-trimmed steering wheel, alloy pedals, rear parking sensors, folding door mirrors and various interior and exterior styling tweaks.Renault diesel engines are generally very good, and the 130bhp 1.9 dCi is no exception. It gives the Megane CC a top speed of 127mph and a 0-62mph time of 10.6 seconds, and while neither of those statistics seem particularly exciting I'm here to tell you that the car feels quicker than that - or, at least, it never feels any less quick than it needs to. "Green" figures of 48.7mpg combined fuel economy and 149g/km CO2 emissions (the latter obliging you to pay £125 a year in Vehicle Excise Duty) are the second best in the range, beaten only by those of the 110bhp 1.5 dCi automatic, which really is slow.The downside of the engine is that it dominates the car in several ways. First of all - and despite both Renault's own claims and the stated opinions of several motoring journalists - it's a bit gruff, barking into life from a cold start and actually making the car vibrate when it's sitting at tickover. Its considerable weight (diesel engines being naturally heavier than petrol ones) also has a noticeable effect on the ride and handling. The nose feels like it has to be perusaded to turn into a corner, and the front end lumbers over bumps and crests.For all of these reasons, I get the impression (though this can't possibly be true) that Renault created the Megane CC as a car to be powered only by petrol engines, realised at the last minute that it had forgotten customers might want a diesel, and shoved one in without having enough time to attend to the suspension settings or refinement.But I can't really complain about this too much, because after a couple of days of coughing and spluttering and telling myself that this Wasn't Good Enough and something Ought To Be Done, I realised that I enjoyed driving the Megane CC very much. The noise never improved, and the suggestion that there was an invisible elephant sitting on the bonnet never vanished, but the ride is generally smooth, the balance is great (even though I was always half-expecting the front tyres to lose grip because of the heavy lump in between them) and the steering is wonderfully fluid.You may be wondering what the Megane CC is like to drive with the roof down. I don't know. It's been so cold lately that my forehead would have turned to ice if I'd tried it. What I can say, as someone who is normally no fan of convertibles, is that this one is much better than I thought it was going to be, and if I had to live with one . . . well, that wouldn't be so bad. Engine 1870 cc, 4 cylinders Power 130 bhp @3750 rpm Torque 221 ib/ft @1750 rpm Transmission 6 speed manual Fuel/CO2 48.7 mpg / 149 g/km Acceleration 0-62mph: 9.5sec Top speed 131 mph Price From £21321.00 approx Release date 01/06/2010