So far, just the GTR start button .
I an drooling over the Amuse STTI Titan Gold Ring exhaust... and always a fan of K&N intakes, though don't think the Typhoons are CARB... might not be an issue if/when I get fed up enough to leave Ca. The Stillen is popular but not sure I want to have to take my bumper cover off to get at them.
Don't perceive any issues with suspension to want to tinker with it. Maybe it will as I get more used to the car.
Originally was thinking I wanted a 2013 white wing and/or Evo-R but now thinking I'll leave it well enough alone. Perfectly happen with the NISMO rims, as well but those are so easy to change I might yield to the desire to get some Volk ZE-40's... could enable some interesting tire experimentation, as well since I am curious if there would be any performance improvement with 18's (less rotational mass), as well as tire selection at the cost of some handling perhaps. The rear fog also tickles the ricer in me and I may pop one in there. Probably JDM though the EVO-R looks pretty good, too.
After aftermarket sound in my last couple cars, I was most interested in the integration of the Tech model, which is why I wanted the NISMO Tech... which all works perfect for what it is (last generation). I might ponder a Mirror Link / Car Play capable head unit at some point but that appears a bit dicier with OEM Bose setups so maybe not. We'll see.