Yes they can, the 82 Camaro came out of NO where. The C5 was button lipped for at least 7 years with some people within GM not even knowing about it, and money moved from other projects within Chevy to fund the C5. In a game all about what you have that no one else does secrecy has its pluses.

 

Not really.

Even before the internet, I remember seeing disguised 3rd gens, artists renderings and mechanical descriptions in magazines in the late '70s. By '80/'81, there were pictures of virtually production ready developemental cars in all the mags.

Same thing with the C5, there was lots of evidence...including photographic....at least 2-3 years before they were released. Remember all the black C5 mules and "Cormaros" running around in the mid 90's?