Sometimes it's not so much a case of doing something as being seen to be doing something. One major car manufacturer has had a huge industrial unit adjacent to the Nurburgring race track liveried up with their branding but has spent the sum total of zero miles developing their cars on that circuit. They just need to be seen to be doing so. Likewise, there are a fair number of car makers who jump into market niches with half-baked entrants just to be seen to be taking the fight to the competition. Instead of leaping feet first into the burgeoning coupe-cabriolet sector, Vauxhall bided their time, developing their Astra TwinTop properly and it looks set to do very well.

I'll be honest with you here and say that this class of car is far from a personal favourite. While I can see the appeal in enjoying the benefits of open top motoring coupled with the added safety and security of a proper hard top roof, the models launched along these lines to date have been a rather curious and often unappetising bunch. With so many heavy electric motors to haul about that performance is sluggish, fuel economy dismal and handling dull, these cars have rarely offered much to the keen driver. While the 1.8-litre version of the Astra TwinTop is no ball of flame, it's worth tipping your cap to the engineers at Vauxhall who have at least tried to endow it with a dose of fun.

The 140bhp engine is a familiar fitment amongst smaller Vauxhall models and it offers a useful step up in pep over the 105bhp entry-level 1.6-litre model. There's then quite a step up in power to the range-topping 197bhp Turbo derivative, but then the price hike is sizeable too. Whereas you'll need £500 to upgrade from a TwinTop 1.6 Sport to a 1.8 Sport, you'd need a hefty £1,700 to move from a 1.8 Design to a Turbo in similar trim.

"Astra TwinTop isn't merely an Astra hatch that's had an angle grinder taken to it"

The 1.8-litre model does look to be the value pick of the range. It's available in standard trim but most buyers will choose the Sport model, priced from £18,495. This is supplied with 16-inch alloy wheels, front fog lights, trip computer, steering wheel mounted audio controls and remote control roof operation as standard. Topping off the range is the Design, available from £19,195. This version comes with 17-inch 10-spoke alloys and a sports steering wheel as well as other styling features to add a dynamic edge. Rain-sensitive windscreen wipers, anti-dazzle rear view mirror, automatic lighting control and a windbreak are also all standard. Design models feature automatic pop-up roll-over protection bars in place of the static bars on Sport models, making the lines even sleeker without compromising safety.

The Astra TwinTop's 1.8-litre unit features variable valve timing which means that it pulls cleanly from getaway, the powerplant being optimised for torque generation at low engine speeds. Keep accelerating and you'll feel the moment the valve timing changes, the upper reaches of the rev band being where this engine generates its power. The 140bhp 1.8-litre ECOTEC powerplant was introduced on this generation of Astra and compared to the outgoing model's 1.8 unit, has 14 per cent more power, consumes four per cent less fuel, has improved flexibility and is a good deal more refined.

The generous power output means the new 1.8-litre engine is one of the most powerful in this class, but it's far from being a highly-stressed race engine with peaky power delivery. Thanks to that advanced valve and cam phasing technology, 90 per cent of the 175Nm maximum torque is available from 2,200 to 6,200 rpm. This wide range ensures lively performance and exceptional pulling power even at low engine speeds, making everyday driving more relaxed with less need to change gear. If changing gear isn't your bag at all, there's the option of an automatic gearbox with this 1.8-litre engine. In the manual car, you'll get to 60mph in around 10 seconds if you're keen and yet, with a more measured right boot you'll average around 34mpg. The auto is fractionally slower but there's no discernable penalty in terms of fuel economy.

The TwinTop has some great genetics to back it up. The old Astra Convertible may have relied on a relatively low tech fabric roof, but a combination of sleek Bertone styling, a range of surprisingly punchy engines and some very attractive pricing ensured that it was a big seller. It may not have been the sharpest drive but it was blatantly populist and curiously endearing. The Astra TwinTop moves the game on by offering a folding roof that's composed of three main sections instead of the usual two piece affair. This means that you don't need to fold two huge pieces of metal into the car's rear end, avoiding the strangely mis-shapen looks of some coupe-cabriolets. At the press of a dash-mounted button, the two overhead sections of the roof stack on top of the glass rear window and hinge backwards into the boot, offering the usual benefits of added security and safety of a hard topped car with the wind in the hair feel of a convertible.

What's more, the Astra TwinTop isn't merely an Astra hatch that's had an angle grinder taken to it. The body was designed from the ground up as a convertible and Vauxhall reckon the two cars share at most 30 per cent of their body parts. With excellent chassis rigidity when the roof is in place, driving dynamics approach those of the lauded Astra hatch. Designed at GM Design Europe in Germany, the Astra TwinTop goes into battle against the likes of the Peugeot 307 CC and Renault Megane CC although at almost 4500mm in length, it's usefully bigger than both of these French rivals.

The styling is also better resolved thanks in no small part to that clever folding roof arrangement. The rear end carries over the petal-shaped lights of the Tigra and luggage space is better than you might expect, even with the roof stowed. Utility is enhanced by 'Easy Load', a feature raising the horizontally stacked parts of a folded roof at the push of a button, making cargo easily accessible. Great when you've got an armful of shopping in other words.

Thoroughness in development is the mark of a quality manufacturer and Vauxhall have taken big strides towards that goal in recent years. The Astra TwinTop 1.8 is clear evidence that the company is on the right track.

TOP 4 ASTRA DEALS

The results below show the top ASTRA deals on buyacar

	Vauxhall Astra 1.8 VVT Sport 2dr Auto twintop Convertible
	ETR	Mthly £316	Saving £2,648	Price £17,422
	Vauxhall Astra 1.8 VVT Sport 2dr twintop Convertible
	ETR	Mthly £296	Saving £2,488	Price £16,547
	Vauxhall Astra 1.8 VVT Design 2dr Auto twintop Convertible
	ETR	Mthly £332	Saving £2,794	Price £18,176
	Vauxhall Astra 1.8 VVT Design 2dr twintop Convertible
	ETR	Mthly £311	Saving £2,633	Price £17,302

typical 10.29% APR

PCP finance quote over 48 months,  10,000 miles pa,  deposit of £1000