DirtE30

this mod only works on subaru boxer engines due to the exhaust manifold layout and the firing order of the cylinders? (not 100% on that last part). if you do it on the is350, you'll just end up with a ricey exhaust leak, not the boxer rumble

Well I guess with this mod you just end up with a Boxer engine exhaust leak. I havent quite understood why you would want to give your car an exhaust leak to make it sound better. There is no way that performance can be attained by this modification.