I think that if they went out to the tire it would make it worse.
These pans without any tubing are not too bad (can just hear them with widows rolled up). with tubing I can not hear it at all. side note: if you added more bolts it might also fix the issue.
As for the mat in the middle, I do not know if it would help. there is nothing touching the pizza pan from the bolts to the middle.
I have rear wheel skirts, as for the front, I am not sure yet.
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