heard my name...
to clarify guys, some people prefer the AT like me, so telling a 7AT to "just drive a manual" is irrelevant.
i've driven manuals since i was 13. i've yet to find a manual trans that tops the S2000s gear box; it's just so crisp and short. now that i'm a little older and recovering from a wreck, and now that i've driven cars other than my S2000 (really driven, borrowed for a week+, i have rich family) with dual clutch automatics (the GTR, Evo X MR, 911, and a GTI), i completely fell in love with the options of "track star" and "grocery getter". manual mode offers fast error-less shifting, rev matched down shifts, the no longer needed heel-to-toe technique, etc. all awhile offering the "automatic" mode to surf through town, stop sign to stop light without a sore foot. that being said, the 7AT isn't a DCT, however, Nissan designed and accomplished to produce a traditional clutch packed automatic that mimics and performs like a DCT, they just never advertised it nor got praise for it. and imho, better than a DCT, there's no break in period, there's no clutch burn, there's no throw out bearing to blow out and replace (big issue with DCTs), better and smoother transitions into and out of gears, better maintenance periods, LESS maintenance due to clutch packs, etc..
so no, i didn't throw a shift boot in to make it "look" like a manual, i modified one to fit on simply because the leather and stitching to match looks much more high quality compared to the plastic generic PRND-M that looks like it came out of a Juke (and probably did). to back up that statement, i found a GTR gear selector for a good price and threw that on there.
back to OP, it's easy to do this "mod", just need to decide what route you want to go.
you can modify a boot on the 7AT ring like i did, or you can buy the ring for the manual and throw a boot on there. $40~ iirc. boot will run $20-30 for high quality leather and stitching that matches the rest of the interior. the PRND-M plate easily pops off with 4 tabs, after that, secure wiring and the light bulb socket so it isn't rattling around under the boot.
the tricky choice is choosing a "knob", i call it a gear selector. i bought 2 and returned both, each running around $90-100, and both just didn't fit the Z right, seemed half assed and thrown together. the GTR knob slides onto the shaft and almost fits perfectly; there is a little modification. check out the pic.
assuming you've removed your 7AT selector before, there are 2 notches on each side for the retaining clip. the GTR selector sits a bit lower, and in order for the clip on the GTR selector to lock, two additional notches must be made about .5"s lower. easily done with a sharpy and a $20 die grinder from lowes.
my cousin found my GTR selector off GTRLife.com, $120 shipped, in immaculate condition. brand new from the dealer, you're looking at $450 iirc. make an account, surf the classified, and/or post a thread saying you want to buy a gear selector, they're all over the place and apparently people are wrecking and parting out GTRs all the time.
if you've got any questions, PM me.