For Canadians:
I had trouble finding the Canadian Tire part or the locking plastic cap at Home Depot so I used this from Home Depot instead:
http://m.homedepot.ca/product/produc...957078&lang=EN
I placed a cotton ball inside the sound tube and a ball of paper tissue inside the cap. The cap fits snugly within the soft rubber ring that surrounds the sound tube. It eliminated the fake induction sound and but there's still a fair bit of road and wind noise. It's definitely an improvement but won't suddenly make your car a Lexus.