With the GT R Pro, Mercedes-AMG is squaring up to the Porsche 911 GT3 RS. It gets no more power than the regular GT R, but a comprehensive aerodynamic and chassis overhaul gives it far greater on-track performance. Autocar's Dan Prosser drives the GTR Pro at Hockenheim in Germany to find out if it's as big a step on from the GT R as the upgrades suggest. New videos are uploaded to Autocar each wee
Autocar@youtube
play video