hey there, i put on originally the "original 40 series" flowmaster onto the car and drove it around for about a week. It sounded great but the inside noise was bad. cruizing on the freeway at about 2,000 rpm i couldnt even have a conversation with the passanger. i took them back and changed them out for the 60 series. much, much better, it is a deeper less distinct tone but sounds good when you idle and when you give it some juice. also be aware that there is actually 2 sets of mufflers on mine. there is a center one then that splits into two pipes with mufflers right before the exhaust tips. all in all im happy with the 60 series. BTW that is all i did to the exhaust was change out the rear mufflers. regards.