I bought a g35 a couple weeks ago, opened it up for the first time to install an intake and saw that there is already a plenum spacer installed. I think it is blox, it looks like it. Anyway it looks like it may not be aligned correctly and could be missing some bolts. Since I didn’t do it myself I’m not sure what it is supposed to look like.
here is a video of what it looks like, I am specifically worried about the part by the oil lid.

 

Looks like it's installed corrrectly, those two holes you're talking about on the front outer edge were not used. It should be 18 total bolts, the six in the middle and another 12 around the outer edge.

There are also a couple threaded spots on the back of the plenum that aren't used (it's for the plastic engine cover).