well i did this once.. you can get just about any exhaust for the 6 cylinder and make it work on your car. i did with a yo dude. i got sent the 6 cylinder kit and i ghetto rigged it with a extender pipe i bought from auto zone and drove the .5 miles to the nearest midas, and they guy charged me 80 bucks for a custom pipe to go from the flex pipe to the muffler. (i4s dont have the car under the car like the 6's do and thats why i needed this special pipe made, no bending just one straight pipe.) like i said the guy charged me 80 for the pipe and the whole thing to be welded. overall i spent about 480 bucks on the system and all the things i had to do to it. the i4s are alot harder that the 6's.. i just did my 6 cyl in 30 mins and had no problems whats so ever. but my 6 only has like 600 miles on it,, hehehhehe bolts were still shiney .