The Reiter Extenso has always been one of my favorite GT3-class cars. In 2014 they started with one of their Lamborghini Gallardo FL2 GT3.

The guys at Reiter Engineering modified it by widening the rear axle and adding a few aerodynamic parts to reach the result you see in this video: the Gallardo Reiter Extenso (or R-Ex). Listen to that very particular V10 howl testing on track!