Option 1) Metal Mule a British Company that supplies loads of race and off road aftermarket parts as well as luggage, bike protection, and more. By the way if you order from Metal Mule and you mention that you are a member of this forum you get 10% off

http://metalmule.com/by-product/scre...een-clear.html

Option 2) You could get a lockable clamp on spoiler by Touratech (which is well pricey!, in fact would be cheaper to get a shorter missus ) but might be just the ticket
http://shop.touratech.be/spoiler-for...0z-tenere.html

Option 3) Givi Screen http://www.bs-motoparts.com/en/Defau...V60aAtC28P8HAQ

Option 4) Puig Screen http://www.bs-motoparts.com/en/Defau...hiYaApQ08P8HAQ

I am not sure if Yamaha do one but I never heard any of our members rating it, so it must not be all that.