What is the fine-grained topic of the following text: In addition, it brings a new dimension of excitement over the 600LT Coupé, without compromise to the dynamic purity of the most performance-focused car in the Sports Series line-up: a retractable hardtop to give the choice of open-air driving. Only return the topic.
The new features of the 600LT Coupé in the Sports Series line-up