General Motors' Opel/Vauxhall is planning further fashionable small cars beyond the ADAM three-door hatchback, but said it would not try to emulate the scale of the range offered by BMW's MINI.

Automatic and higher-performance versions of the ADAM are being openly talked about, and next year there will be a 115bhp, three-cylinder one-litre turbo engine similar to Ford's Ecoboost unit for the car. At the Geneva show next month, Opel/Vauxhall will also show a concept car, ADAM ROCKS, giving clues as to how it could introduce a crossover or a convertible.

But there will be no two-seaters to rival the MINI Coupé and Roadster, and no larger model like the Countryman. Nor will the ADAM be available with diesel engines because they would be too heavy and expensive, Opel/Vauxhall said.

The ADAM is pitched squarely at the Fiat 500 and MINI and sits somewhere between them on price. The entry point in the UK is GBP11,255 for the base model with a 1.2-litre engine, rising to GBP14,000 for the top-grade version with the more powerful of the two 1.4-litre power units.

Opel/Vauxhall claims a possible 4bn personalisation combinations, including 60,000 exteriors, 80,000 interiors, 15 different trims and 20 sets of wheels - eventually to become 40.

Claimed unique selling points include self-parking, printed and illuminated roof liners, a revolving programme of exterior colour packs which will be changed every year and smartphone connectivity.

The car was launched in the UK at the Westfield shopping centre next to the Olympic Park at Stratford, East London, where Vauxhall has opened a temporary shop.

Vauxhall expects just over 8,000 UK sales this year, rising to an average of 10,700 a year from 2014. Nine out of 10 sales will be to private customers, with women expected to be 60% of buyers.