The photo below is the rear of the car where the right side of the car meets the rear where the tail lights go.

Is this seam sealer or glue?

Can I just grind this off, add in the tiger hair then seam seal?

Or

Just use seam seal?

Or

try and get someone to run a weld seam down it?

Or what?

Sorry for all the post, thanks for the help.

 

just put seam sealer from both sides for extra protection