Oooh car thread! Thought I'd chime in here....
Currently driving my second Impreza - '02 Bugeye WRX, slightly "breathed upon" with Cobra up-pipe and center section and Hayward & Scott backbox, high flow panel filter and a basic map.
I've been down and huge 3" Jap can backbox path, was fun but LOUD. Got it out of my system, now I'm too old for that haha. Now it's just a lovely rumble.
Front 02 sensor has chucked me a CEL recently, not looking forward to the fight of getting that off. I've read horror stories hah