The convertible Camaro has structural bracing to make it as close to the rigity of the standard Coupe, so they could easily do it for T-Tops. Now if the NHTSA says they are too unsafe, that is a different story. Z-28's were originally low optioned light weight track cars that had better balance than the Heavier engined SS cars. They were more auto-cross style cars, the RS being a modification from that as the off-road rally type. Personally I love what they have done with the Z-28, but they should have put the LT-1 in it. Coming from the factory without a radio and things like that do not appeal to people the same way as they did in the 60's because you pay more for less now with that car.
2014 CTS-V... with some go-fast bits coming