I already did that, helped a lot, but I still get the little "bzzzzzzz" at those rpms. When I put my finger on the ribbets, it's gone. Hence the question...
As I said, it's so vague that my girlfriend tells me to take my prozac every time I ask her if she hears it
That panel starts whistling on mine right at 43MPH, and it's loud enough I can almost hear it with ear plugs in.
Martin, you could try shimming the plastic rivets (ribbets) with a thin plastic washer, to take up some of the slack and tighten them. One other thing I was considering was using rubber well nuts and screws instead, but not sure if the panel would sit flat enough after that. With the screws, you would have to take the shield off any time you wanted to remove any other plastic, but not a big deal.
Of course, you could do the unthinkable, and listen to your GF. Either that, or use ear plugs, and enjoy peace and quiet.