nosram matrix 2007
 

OK eventually as happens,
my top has come of my speedo not just the heat sink but the top cover that covers the fet, i know some have already had this problem, but how and what do i need to fix this,

I suspect the right answer if a good quality heat paste, that will harden.

My answer would be to "CAREFULLY" place a very small dot of superglue, one in each corner, and refit. When I say small dot, I mean pin head sized.

Any None conductive silicone will hold it down and re-seal it again.