i talked to the guy from royal muffler... he said the exhaust is a custom "one-off" for now. it would cost about $2,300 and he would need your car for about a week to customize and make the exhaust. one cool thing is that unlike the joe-z exhaust, his exhaust goes out to four separate mufflers (may be a little overkill though). he is not thinking of putting into production unless there is high interest to buy (this would bring down the price significantly). he didn't have dyno numbers for it yet as he is in the process of developing a cold air intake system and he said he wanted to wait until he had all of it done before dynoing the car.