I own a GReddy Evolution catback, I've it had on my car for awhile now and I have to say I love it. It's a nice deep tone that can scream when you hit the pedal but crusing around the city it hums and wont get you pulled over. It looks pretty nice and has a great tuck desgin for cars with ground clearance issues so you wont have alot of can scraping. Although it will still happen, it's least likely too.
It's a pretty high qaulity exhaust IMO.
