I think this link might answer the question about the rear spoiler and the brake light:
Nissan Spoilers - Nissan Car Spoiler 370Z, Altima, Maxima, Versa
If you scroll down about 1/4 of the page you'll see what I mean. It shows that the spoiler is available painted or unpainted and no light is included.
Also, they use the term "rear spoiler with integrated 3rd brake light" and the word "integrated" means: combining or coordinating separate elements so as to provide a harmonious, interrelated whole. So wouldn't that mean the light is part of the trunk and the spoiler is a separate part making it appear to be one piece?