Here is the correct answer appearing in another thread:
This has been discussed before. The empty slots are for pliers and a screwdriver equipped in other regions (similar to how the US doesn't have a functional fog light). Nothing to worry about, you've got the same thing as the rest of us.

Originally Posted by Nissan USA Technology Dept.
I’ve learned that the indentations in the foam around the spare tire in the 370Z are for a screwdriver and pliers. These tools are only included in cars destined for Global Overseas Markets or places other than Japan, the Americas or Europe. I believe there are regulations in some of these countries (like the Middle East) for these tools. So just to be clear nothing was left out for the U.S. customer.



Thanks for asking this question. It gave me a good reason to find out about this.

I don't even want to look at the spare tire section after what I found when I removed the front license plale bracket.