Opel will unveil a new Astra four-door sedan on 1 November at the Istanbul motor show.

GM has chosen Turkey for the launch due to buyer preference for four-door sedans in the region. The new model will be sold mainly in eastern and central European markets and will be made in Gliwice, Poland.

AvtoVAZ is also likely to assemble a Chevrolet-badged version for Russia. There won't be right-hand drive versions for Vauxhall, however, as UK buyers in the lower medium 'C' segment prefer hatchbacks.

Opel will emphasise the Astra's roominess and 500 litre boot. Unlike the Twin Top and hatchback models, the Astra sedan is built on the wagon's extended 2,703mm wheelbase (length/width/height: 4,618/1,754/1,458mm). A range of two petrol and two diesel engines with outputs between 90 and 140hp will power the new model. It may be a short life for this model as Opel is expected is expected to give the Astra range its first facelift at next year's Geneva motor show. The current Astra range was introduced in 2003.

GM starting building an all-but identical car to the new Astra sedan in South America in October 2005. Sold in Brazil as the Chevrolet New Vectra and exported to Mexico as the Astra Maxx, this model is also expected to be the basis for the Saturn Ion replacement due in the US at the end of next year.

A Vectra but not as we know it