You can skip the moulding. It will rub the roof if you place the fairing about a 1/4" above the roof. You could put down some clear vinyl first to prevent it. The truth is, the rack is very quiet and it's not necessary. I've help install 3 of these and we all ordered the trim. None of us used it.they replied quick when i asked to add the noise reducing trim to order. So fingers crossed hah.
I'm not sure it shows the gap well enough, but you can definitely see the screw hole placement for the fairing I used. I hope I saved you the $12.00!
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