should all the 05 and up models fit the 08's. liek buying an exhuast off an 06? would everything fit normally?

 

I'd hate to tell you yes on something and it not work. I know that brenspeed took delivery on an 08 a month or so ago and can give you a def yes or no on pretty much any mod you can think of. Contact them, their customer service is A+.

But I'm quite sure most everything is interchangeable, maybe with the exception of a used tuner that has a different cpu code than your vehicle.

 

The only difference I know of that affects some aftermarket items is that 07-up, the upper radiator hose is different. Installing a ProCharger on 07-up GT is easier and less time involved due to not having to relocate the upper radiator hose.
Valve covers were changed in 07 and use less bolts to hold them on. Which probably means the heads have different part #'s, but would still allow the use of the same headers.

Exhaust would be the same 05-08.

There shouldnt be a problem with 99% of aftermarket parts swapping or year to year swapping.