Seanus has fixed the speedy tyre change time of the Ginettas to bring them in line with the other cars. In fact, the Maserati and Porsche now have a slight advantage in tyre change time:
Maserati & Porsche: 20 seconds
All Ginettas & Mustang: 25 secondsDownload this
and extract it into assettocorsa\content\cars, overwriting existing files.