Hey Guys, 2010 G37 Coupe Time Attack car here. I've kind of locked down my mechanical grip more or less to the cars extent so I'm ready to start looking into aero. The only body/aero modification to this car is the Z1 Front undertray, and the stock lip, everything else stock Sport package. I want to hold off on a large splitter/wing for now as those bump me up to the next class in Nissan Challenge, but I DEFINITELY need more rear downforce. The biggest aero drawback of the coupe specifically that I find is the rear bumper. I have a single exit ISR exhaust (driver side) and there is just a huge opening where the oem muffler used to be. That thing has got to be a gnarly parachute. I want to cover it and add a rear diffuser.

So my question: Is there any kind of actually functional rear diffuser or undertray for these cars, or has anyone built one? Everything I've found is aesthetic only, other than the libertywalk/VSaero being semi-functional. If not, I am going to try to make one from a thin aluminum, as I've seen people do in other car forums. I would like it to start right behind the differential. The problem is that there aren't very good mounting locations. And I don't want to cut the rear bumper above the license plate (still a street car technically). Help!

I'm also not opposed to getting side splitters right now too. But our non-ipl side skirts suck so I'm wondering if they will even work properly with splitters. Here's one I found: https://www.drivenbystyle.com/2008-2...BoCpqIQAvD_BwE
^Would also help from kicking up rocks along the side of the car with my fat front tires.


Pic for attention