King Motorsports Unlimited, Inc.King Motorsports said:We have completed initial test fitting of the Mugen airbox on the 06+ Civic Si. We have found while the airbox physically fits the USDM Si perfectly, the ID of the USDM intake hoses are slightly too small to fit the Mugen airbox. We are working with Samco to produce a correctly sized intake tube that will also have a provision for the USDM mass air flow sensor. More updates to follow.
And thanks for posting the update, I'm interested to see/hear what they may e able to come up with! (Although I'm sure it will be months down the road)