Folks -- I tried the magnet route with Neodymium magnets and it was only partially successful.
The total success was achieved by stitching some Industrial class velcro to the hood Flapfront and sticking a bit of the other side(Hook side) to the top front of the windscreen pillar -- this has two benefits --1- it stops the flap blowing outwards and thus allowing rain in at the corner of the hood and 2- it holds the sidescreens in at speed.
Why the factory doesnt do this as standard I dont know -- I even proposed a design for the hood front to eliminate the problem, sent it to the factory and they promised to sort it out the following October -- that was 3 years ago and the hoods are still as they were when I was in the factory last!!
The Velcro DOES sort out the problem and I found it way better than magnets
Cheers!
