The Volvo 300 series was the successor of the Volvo 66, itself the successor of the Daf 66. Volvo had bought Daf and continued production with some changes and improvements. The cars were referred to as Daf, even after the name change. The variomatic transmission basically allows you to go as fast in reverse as in forward. These cars were successfully raced in rally competition, and later on, were raced in reverse in demolition derby type races. There are some videos on youtube, but most are not in English.