The product you are talking about is the Hliner from B-Quiet (the same people who make Brown Bread). I have it - it's a good product, and it's easy to install. You just cut it to the right shape and use your original plastic plugs to attach it to the underside of the hood. It might be a little tricky to get it just right if you've already discarded your original liner though. The only catch is, I believe it's actually a bit thicker than the original, so I'm not sure it will solve your SC clearance issue without cutting a hole in the middle.



http://www.b-quiet.com/hliner.html