Having to use ear plugs at speeds over 30 km/h due to the noisy mid-size Isotta windshield wasn't fun. I ordered and this week installed a laminar lip.
Works fantastic. Don't need ear plugs until about 70 to 80 km/h. The windshield itself was up to my mouth level. The lip goes to my nose level. One day I'll raise it sightly higher for even quieter ride at higher speeds. Pics attached. The lip company advised me to buy the model for BMW 850/1150GS, as they don't have a model under the Vespa link.