Why aren't you including non U.S. sales? Simple question.
Also, you think the 5th gen program cost $9 billion to develop??? Holy crap dude, I want whatever you're smoking. For real, that is so far off, I can't even laugh about it. The total Curiosity Mars rover program only cost $2.5 billion, to send a one of a kind, and one of the most advanced man made creations ever 35 million miles away. The Camaro program cost 3.5X that? GM is extremely stupid I guess.
GM is good at it the W body platform in the late '80s cost GM 7 Billion so its not a stretch for the new Camaro to cost 9 billion. The damn thing doesnt share a platform with anything else built in NA IIRC.