Some sort of European hatchback.
Couper isn't a soldier, if anything, he shoots things for fun. Before the war, on Cybertron, he had a gun shop. Trust me, he'd rather do skeet then fight in a war and the other Autobots know it. Couper is also a European Autobot, a Frenchman. He landed on Earth in France and largely remained in hiding until The Event. Couper fought a few Helicons.
Blue, Grey and Black.