Someone in General Motors obviously has a sense of humour - hence the name Frogster for this quirky roadster concept based on the Agila. According to the GM advanced design department the Frogster is "what a car for the PlayStation generation might look like. We want to connect with ravers, snowboarders and people we've ignored in the past".
The look of the VX200 (Opel Speedster) can clearly be seen in the Frogster. I'm sure the intention was to create a more laid back version of the VX220 for those who don't care about performance.
The concept car was built in Italy by Bertone, who build the Opel Astra Coupe Convertible. The practical but rather staid Agila is not exactly the ideal basis for a sporty model, but the emphasis on the Frogster is more on fun rather than out and out performance.