When I worked at Pininfarina Studi e Ricerchi in 1995, I was asked to design a special exterior to be based on an Aston Martin Vantage 600 chassis.
Two different sketches were chosen by the client (the Sultan of Brunei) to create the special models labelled, AM3 & AM4.

AM4 was a muscular curvacious shape with a front end reminiscent of older DB5-6 models.

AM3 was a more modern and sleeker shape with  contrasting extremities inspired by Aston Martin’s classic grill shape.

The only sketch I present here had to be reworked without the rear diffusers and central exhaust pipes. 

After I had left Pininfarina, the cars were completed by another designer who successfully managed to accurately convert my sketch ideas into the finished cars.