As an insider that works with camouflaged cars every day, I know it's frustrating to the public to see camo on cars that have had massive ad campaigns already like the Proto Z (I refuse to call it the 400Z as I'm still hoping Nissan calls it the 300Z). At this point, the production car will certainly be close, but likely different in many small ways when compared to the Proto Z. One of two outcomes will occur. Either people will like features of the Proto Z better and complain about how Nissan dumbed it down for production or they will think the production Z looks better and Nissan's big ad campaign will be outdated, It's a no-win situation, so the best thing to do is hide the final details until it's 100% ready. The main reason for the ongoing camo though is that pre-production cars are far from perfect. These cars are not built on the production assembly line and haven't gone through anything close to production quality checks, so if a car "looks" like a production car on the street, people will assume it is and their impression will be severely tarnished if they see poor panel gaps, missing trim, mismatched panel colors or 3D printed parts that aren't quite right. Anything that's plastic would not yet be grained. Manufacturers add graining to the tooling after they are sure the plastic parts will not need to change. In addition, many of these cars started life many, many months ago before the Proto Z reveal, so they never got a real paintjob. Most get a simple black or white paintjob just to cover the metal so they don't rust - think rattle can. They were camouflaged when built, so removing the stickers now would not only reveal terrible looking cars, but much of the paint would peel off with the sticker removal. Depending on the car's intended usage, some parts are never installed and others have been removed or cut up to fit test equipment. Prototypes are not meant to look good. They are built for testing. Some are powertrain calibration, others NVH, Vehicle Dynamics, brakes, etc. The engineers usually don't see what the production car will truly look like until the public reveal. We see the same ugly prototypes as the public.