What the... N00bish!? How dare you! lol
FYI The visual tips on the back of an IS-F are plastic and fake. The 'real' exhaust tips sit behind these.... so i would suggest you're the noob lol
Unless you guys in the US have a different exhaust set on your IS-F's?
Also the MR2 twin exit exhausts (especially on the turbo) are not as good performance wise as the single exit systems like the Blitz Nur Spec R for example.
If there is one thing i know about, its exhaust systems and Toyota engines.