i've used kakimoto.....straight flow.....which emits something like an rb only thing it sound rougher....
another straight flow brandless.....from a k20 which sounds exactly like a vtec......during cam on........
a big box fujibutso.......that sound like a superbike........

and when the engine.....is started early morning when its cold or the battery unplugged.....it will sound like a scooby.....heheh.....

u've got to remove all the centre boxes to have some crazy exhaust note......but when u are driving on the streets beware, u've got to watchout for officers cos they can hear you blocks away before they can see you.......heheh......

highwaystar, your car is a 323i right? Very nice sound. Thx you

Mantap la bunyi keta bro highway!!