I have also recently noticed the dash "flickering " with the engine on ...and i was trying to work out if it always had done it or not. ....however yesterday I had a "real" problem ..it involved the egine cutting out on the motorway ..the speedo reading wrong ...a total nightmare
that was all down to to the positive lead on the battery being loose , it was making an intermittent connection ...anyway I have just checked... no flicker

hurrah...so get your seat off and check the battery connections ...apologies if you have already done this .
I think the terminals on the battery are easily knocked or loosened ...I may have loosened mine while playing around fitting a tail bag ..it involved a lot of seat on seat off ..oh and a bit of swearing
