I went to the Nissan dealership at the service/parts desk, I explained which part I needed, he flipped the monitor over to make sure that was the right part. (since I didn't know the part number or exact name. )
Usually the part won't be in stock because not many people order a/c vents for Z's lol
You can also check out courtesy parts, good oem stuff. Ebay sometimes works too.
http://www.courtesyparts.com/3....html
By looking at the assy picture you can tell which part and number it is that you need, erhm I can't seem to find the side vent though on the site. You just might have to drop in to your local Nissan or give Nissan of Texas a call.