There is a slightly more elegant and permanent fix for this.
Take off the plastic piece at the latch, then unbolt the latch from the roof, and go get some washers from any place that sells hardware, get like 6 to 10, varying in thickness( i forget how many it took me, they are dirt cheap anyway) Put the washers between the roof and the latch plate. This moves the fulcrum out a bit and gives your latch a little more force. Use different amounts and thicknesses of washers to find the perfect spot where is holds the sunroof down, but doesn’t take extreme effort to lock shut.
Now your sunroof will not whistle anymore..... well at least until the rubber seal starts to crack and come off
-Matt