Ithink the issue really is that when travelling with the hood up, once you get to about 60MPH or 100 Kph the screens are "Sucked" outwards. OK if it's dry, but a great source of water if it's pi**ing it down!! I do know in the past people devised all sorts of solutions to "attach" the screen to the upright of the screen, but this would be v.difficult with the newer uprights.
I think some sort of turnbuckle arrangement is required -- I am trying to envisage this and will continue to exercise the grey cells until I've solved it -- that is unless someone else has the bright idea first!!!
I know that keeping the hood down is the best solution, but in the current weather pattern here in Ireland that is just not on!!!!
Cheers!