Complex sentence: In 2005, Land Rover launched another model under the Range Rover brand--the Range Rover Sport, which was based on the Land Rover Discovery platform, but the new Range Rover Sport has the latest Range Rover platform.
Split into simpler sentences: In 2005, Land Rover launched another model under the Range Rover brand--the Range Rover Sport, which was based on the Land Rover Discovery platform. But the new Range Rover Sport has the latest Range Rover platform.