08 Preformance parts

[Little General]

My brother in law is an engineer at Wix filters and checked the 03-07 filter against the 08 . They are the same. The reason they have different part numbers is the intake on the truck has a different tube but the same air box. A drop in K&N will fit but he said the Donaldson will flow the same and is actually a pretty good filter. He came up with the conical filter design years ago and the new corvette filters so I believe what he says. I know I spent countless dollars on my 04 and never seen any improvements worth what I spent. Did the exhaust help with performance or mpg? How about sound, we got a corvette engine that sounds like a mini van.