Iain Dooley, PA senior motoring writer, lifts the lid on BMW's open-top 3 Series.

Engines – Like its saloon, Touring and Coupe cousins, the 3 Series Convertible benefits from a wide range of efficient and willing petrol and diesel engines. Low-mileage drivers will be fine with a petrol motor, while even with the top down there's no refinement penalty for choosing an oil-burner.

Exterio – This generation of 3 Series is one of the most handsome produced by BMW. Equally stylish with the roof up or down, opting for an M Sport variant adds an extra layer of sportiness to its looks. Also, a contrasting roof colour can make all the difference to its appearance.

Interior – It's all familiar stuff inside the 3 Series Convertible, what with the solid build-quality and premium cabin ambience with the roof up. There's just enough room for rear-seat occupants, although that option disappears when the wind-deflector is in place.

Driving – Despite the absence of a fixed roof the convertible is still regarded as a good car to drive and boasts all the positive qualities of the rest of the 3 Series family. Roof-down motoring is pleasingly civilised, and if you pick the right engine you can choose between rapid progress or impressive economy. Or both if you opt for one of the high-end diesel motors.

Ownership – As far as the ownership experience goes, the 3 Series family promises one of the best in the business. In drop-top form the car is easy to live with, reasonably practical and surprisingly affordable to run. Granted, with the latter you'll need to pick your engine carefully, but a middle-order diesel will give you all the go you need, offer plenty of refinement and deliver above-average economy.

What to look for – Viewed by some as a status car, be vigilant for the usual parking dents and kerbed wheels that can signal a hard life in the city. It's also doubly important to check the condition of the metal folding roof and that it works flawlessly. A thorough test-drive and a full service history are also vitally important for total peace of mind.

Model history – 2007, BMW launches a convertible version of its new 3 Series. The two-door, four-seat car comes with a wide choice of petrol and diesel engines. Modest standard kit levels boosted by a generous choice of cost-option kit.

Reasons to buy – Image, well-built, good to drive, wide engine choice, versatile metal folding roof.

Reasons to beware – Check for abuse especially to roof, image, rear-seat space.

Pick of the range – 320d SE.

What to pay – 2008 08 �16,550; 2008 58 �17,275; 2009 09 �18,950; 2009 59 �19,875; 2010 60 �22,625; 2010 10 �21,575; 2011 11 �24,625. Showroom prices for cars in A1 condition.