Parts for '07-'08 Yaris on '09+ model?

[Creamed Corn]

Hey whats up everyone? I'm new here, and no Yaris just yet, but I just had a few questions primarily regarding some performance parts for the Yaris. First off, i'm aware that the Yaris is based off of the same platform as the xA/xB which have a massive following/aftermarket. However, after doing some research, I noticed alot of parts, like the HKS Hi-Power exhaust for instance, are only listed for '07-'08 Yaris's (Yari?). I'm aware of the cosmetic differences, but are there any real mechanical differences between the '07-'08's & the '09-'10's? Or are all parts backwards compatible between the the two generations? Any and all help is greatly appreciated. Thanks!