Wow, you really dug up those numbers quickly.
Have spent the last weeks cleaning out my living room, removing all old Honda NSX parts lying around and finally put them away. But the NSX literature corner is still a bit of a mess though 
Going from definite lift to some serious downforce on the 2002 NSX-R is a good example of the work done by Honda on the NSX-R model.
It's also nice to see that the Cd value of the NSX-R was measured at 0.34 whereas the standard 2002 model was given as 0.30.
I think that might be a very good example of how the increase in downforce results in a HIGHER Cd-value.
Now consider this: Look at the picture of the airflow over the NSX-R and see how high that car is. And then remember how basic the OEM Honda NSX-R front undercover is.
Now lower this car about 1", then add an undertray more like Greenberet made for his own NSX and then I wonder what the result would be.
Am also wondering how much difference a airsplitter might make, although I usually don't like their appearance very much.
