YuYu...also coming from an engineering background (yes that rocket scientist under my name is real..well...kinda) I don't have numbers but know the major loss points. I'm sure if we had the equipment to do it, we could. However, the restriction points are common from car to car. If you can tune those points then you're set. The only question is what is the right tuning point? 2.5" exh, 3"? Maybe a bigger throttle body. Or it could be tuning the fuel delivery. There are a lot of factors that we, as engineers, could get wrapped up in...that's why an aftermarket exists, because it's a full-time job for those people. Sure you and I could run a CFD for the stock set-up, probe it, and then optimize...but we do have bills to pay. And that would take time, even doing it quick-n-dirty.
(that's why I haven't yet...)
BTW...where are you working? You moved up here, right? I work in Bloomfield for a Consulting Engineering firm. Still trying to find Aerospace work (hence the sorta Rocket Scientist...) PM me if you don't want to be too open out here!
And yeah...I know all about the bottom line...that's the reason I live at home right now.

Still...for enthusiast cars that are limited run, a slight initial loss that will increase total sales should be done.
Sorry for the thread-jack...your dealer still blows. I wonder how mine will be regarding mods...