Probably been written a thousand times, but heres my fix.
Get yourself 12, 12-15mm common garden variety tap washers. Pref soft. Get 6 X 5mm stainless cap screws 30-35mm long and 6 X 5mm flat washers. Remount your windscreen using the tap washers one behind, one in front times 6.
While you're at it, don't overlook remounting the instrument panel as well. In my case, it was loose, enabling the self tap screws to vibrate against the metal mount plate. I just made some extra rubber mounting pads from an old inner tube to pad it out a bit more and tighten things up. I did both the above and the result was perfect.