The new Renault Megane CC doesn't look a million miles away from the last one, which is good news as the last one was my pick for the best-looking coupe-convertible on the road. There's still something of the DNA from the old Megane drop-top, but its backside has grown somewhat between models.At GT trim there's a body kit that adds a dash of intent to the looks, but the CC's profile comes off as a little smoother, a little rounder.A sumptuous interior at GT TomTom trim level is decked out in two-tone and the dash looks sufficiently different to anything else in the sector be interesting while remaining simple to use.Soft-touch plastics around the interior also please and though seats can be adjusted they're not the most comfortable while, as ever, rear seats are best used for shopping or small children.There are 211 litres of boot space with the roof down, not bad for the sector, and a decent 417 litres when the roof is up.Still, that shopping will be travelling in style with the roof down, which is really the whole point of a convertible. It looks good with it top down - it closes in around 21 seconds - but does it drive well with the roof down?Well, no it doesn't. Scuttle shake is immediately evident through the body of the car when the roof comes down, sending judders through the Megane and passengers alike. Handling becomes less responsive and ride comfort is compromised, even on smooth road surfaces.Travelling over cobbled roads in the French countryside, it felt like the Megane CC might start to lose bits, while travelling at higher speeds was blustery and revealed a noisy vibration around the windscreen. The extra weight at the back with the roof stowed makes it a little sluggish to direct too, while the steering is too light.This is a shame because the new Megane CC rides and handles well with the roof up, courtesy of a capable 110bhp DCi turbodiesel engine, mated to a brand new six-speed automatic gearbox.With this engine it's capable of 118mph and sprints to 62mph in a leisurely 13.2 seconds, so it's no ball of fire but the turbodiesel has 177lb-ft of torque, which provides a decent surge in the mid rev range.What's more it will return a very impressive 57mpg combined, if you can manage the official figures, and emit 130g/km.The new dual dry clutch automatic gearbox is able to pre-select gears, making for lightning-quick shifting and the gearing feels about right for the coupe-cabriolet, though there's a little delay in finding the sweet spot in the rev range so the gearbox has to hold on to lower gears for longer.Nevertheless, the new transmission can legitimately claim to offer the comfort of an autobox with the frugality and response of a manual box.Models with the dual clutch also offer creep for low-speed driving, hill start and hill descent controls. Meanwhile, all models with the new transmission feature gear shift indicators to educate drivers as to the optimal shift points. Stop-start also features - with the emphasis on quiet, fast vibration-free start-up - meaning improve fuel economyThe Dynamique TomTom trim provides decent kit levels, including air con, alloys, electric windows, cruise control, TomTom satnav and Bluetooth.Front-, side- and thorax airbags are standard as are ESP and anti-submarining airbags, designed to stop you slipping under the seatbelts in a shunt.It's a decent all-round offering and the interior raises the bar in the sector again. Like many metal roof convertibles, though, it proves a bridge too far to make the Megane handle anywhere near as well with the roof down as with the roof up.If buyers can live with the trade-off for a smart car with lots of interior kit and strong powertrains the Megane might hold its own against new coupe-convertibles due in the next couple of years from Ford and Vauxhall.