Anyone install aftermarket Exhaust and intake on IS350? Question is Does it make a big difference cabin noise, or is it ok, almost as if its unnoticable or noticable? Debating whether to get intake and exhaust because of cabin noise if it is really bad. Any help will be appreciated.

 

intake : yes, only if you are in higher rpm range.
exhaust : I am not sure since I dont have one on mine, but pretty sure its noticable in cabin.

 

For the Intake, it gets pretty loud during higher RPMs when the VVT-i kicks in.