A compact convertible that delivers huge open-air thrills – that's BMW's 1 Series, says Iain Dooley, PA senior motoring writer.

Engines – It might be a convertible but you can still have this open-top 1 Series with a diesel motor – it wouldn't be a BMW if you couldn't. And if you're familiar with the brand you'll know the oil-burners are first class. The petrol engines are pretty good too, a quieter if you only do a modest number of miles in a year.

Exterior – This first generation 1 Series will always divide opinion, and for some the two-door models cause the least amount of head-scratching. Removing the roof does much to flatter the car, yet it's not a bad looker with the fabric lid in place either.

Interior – With the roof up it can get a little gloomy inside as the default colour for the car's cabin is black. That said, there's plenty of space up front for two adults – the rear seats are a little limiting, though. Quality-wise it's as you'd expect from BMW, and with the roof down it's even better.

Driving – It might be a rear-wheel drive compact convertible but it's fair to say this 1 Series is bought because of its open-air potential. As such, don't expect M3 levels of performance here. In reality the 1 Series Convertible is a car you don't hurry, although opting for a high-performance motor does make the overall experience even more pleasant.

Ownership – A compact car, the 1 Series Convertible isn't going to be a chore to pilot around town. If you routinely rack up the miles the diesel options will impress, while low-mileage owners should be similarly bowled over by the smoothness of the petrol units. The roof operation is swift and needs little user intervention, and refinement levels are good with it down.

What to look for – With many cars spending their life in town, always look for parking dents and the predictable kerbed wheel damage. The latter could be hiding more serious damage, which makes the test-drive and the existence of a full service history even more important. Also, look closely at the condition of the car's roof, as any damage could prove costly to repair.

Model history – 2008, BMW launches a convertible variant of its 1 Series model. Essentially a coupe version with a fabric drop-top roof, this model boasts a model level of standard equipment alongside a surprisingly generous number of petrol and diesel engines plus a wide choice of trim levels.

Reasons to buy – Brand image, drop-top experience, economy, engine refinement.

Reasons to beware – Not as driver-focused as the Coupe variant, looks, cabin and boot space.

Pick of the range – 120i SE

What to pay – 2008 08 �13,175; 2008 58 �13,650; 2009 09 �14,590; 2009 59 �14,700; 2010 10 �16,475; 2010 60 �17,200; 2011 11 �18,525. Figures relate to showroom prices for cars in A1 condition.