Does anyone have any experience with windshield spoilers that direct air over your head? I am thinking about buying one and using it for distance traveling. Both my big windshield and my stock windshield on my WeeStrom have an upper width of about 12" and I would be interested in one of the clip on models that have 2 clip points and not 1 in the middle of the shield. Interested in name brands, cost and where to buy. Do you peeps find them effective?