After Bugatti's success with the 16.4 Tremendous Sports car, an open-top, soaped-up Grand Sport was inevitable. Not long after the Tremendous Sport launch, Bugatti started receiving inquiries about whether there would be a Grand Sport version and they were instantly drawn to the idea.
Source: http://indiancarz.com/index.php?tid=397
Source: http://indiancarz.com/index.php?tid=397