Having owned myself several muscle cars throughout the years, all I can say is the new Camaro, unless they improve its appeal and looks, is not going to beat the sales of the new Dodge Challenger. Many of my friends in Detroit have seen both cars very close, many of them are GM purists and they say the Challenger has a lot more appeal and looks more like its predecessor. They all say the new Camaro has very limited headroom and vision is limited through the windshield. Remember the poor sales of the new GTO caused its cancellation.
Why it did not sale as much? The new GTO has the appearance of a FWD Cobalt. If it was not for the badging, you could confuse it with a GM FWD car. by the way, the new Mustang has sold very well. A friend of mine owns a Ford dealership and cannot keep enough of the GT versions in the lot; they are gone within days. Every body in the industry knows the Mustang created havoc on the sales of both the Camaro and Firebird and at the end, they got cancelled.
For both the Challenger and Camaro to be succesful, they need to have a competitive price like the Mustang, and offer of variety of choices too. It is a vicious business; even Ford had to cancel the GT-40 since they could not compete against the Dodge Viper. Although its built in limted quantities, the Viper has been selling vey well since its introduction; specially in Europe. I have seen many Vipers in Germany, England and France. The Europeans love them.