Actually, Europe is unique by it's 60s Coupes. Citroen Ds 21 Chapron, BMW 1600, Ford Capri, Mercedes 280 SE, DeTomaso Pantera, Austin Mini Couper S, Jaguar E Type, Porsche 911, etc. America also gave some of the best and most popular cars ever: Ford Mustang Mach 1, Chevrolet Impala, Corvette Sting Ray, Camaro SS, Pontiac Gto, etc. Now, when I'm thinking about 60s cars, I found that you can't make just 3 chassis types for all of them. Those years factories wanted something new and different. My opinion is to take 1 American muscle (square body), and 2-3 European (misc square-round) chassis. This is just my opinion.
Just lovin' cars, that's it!