The second-generation Agila makes its debut at the IAA international motor show in Frankfurt in September and will be available in dealerships from next spring.
Aimed at women aged 25 to 45, the model will compete in the urban mini-car market against the Fiat Panda, Renault Twingo and Suzuki Splash.
StrawberryFrog Amsterdam won the business in a pitch against McCann Erickson and French agency Australie. The review was overseen by Olivier Danan, European communications director at Vauxhall Opel, who described the launch as the manufacturer's most important of the year.
The agency is planning a campaign that will position the model as a 'fun' rather than functional car, and make the link between the lifestyles of young urban women and the Agila.
Vauxhall sold a total of 301,679 cars in the UK last year, according to the Society of Motor Manufacturers and Traders, giving it a 12.9% share of the market. This compared with 317,353 the previous year - a decline of 4.9%. Across Europe, GM Europe sold 28,000 Agilas in 2006, down from 37,000 the previous year.