SUBSCRIBE for more great car videos: Mercedes AMG GT C full review: br The massive specs of the Mercedes-AMG GT C Roadster's 4.0-litre twin-turbo V8 engine only tell half the story. Seen through the lens of Arizona's wide-open spaces and epic road routes, this is a supercar-slaying grand tourer that puts far more expensive rivals in the shade...br br More Auto Express videosbr Car reviews playlist: Mercedes E63 AMG video review: br More on AutoExpress.co.