Dash misting up after it being in heavy rain or misting when  in the sun?

There are two opposing thougths on this.
  - dash is not well enough sealled therefore water gets in and causes the misting.
  - dash is too well sealed and does not allow moisture out.

Early on the accepted method was to pull the dash appart and seal it up with mastic. There is Cupid Stunts early fix.

LINK to early repair manual

However it never seemed to be particularly effective, apart from perhaps the use of silica gel, but that is only going to last so long before it becomes saturated.

I took a differnet angle on it that there was no way to stop moisture getting into the dash, but what was needed was to make it easier to let the wet air out.

https://www.apriliaforum.com/forums/showthread.php?289438-Alternative-misting-clocks-cure&highlight=drill

This did work. after riding in heavy rain for some time, there might be some dash misitng but it soon cleared and did not return.

Personally, I think this is the better option but both are here for you to look at and make up your own mind.