if you have breaks on the grille you might get welding pins from a stud gun and you can use a soldering iron to melt the stud into the plastic to bridge the break for structural support so that your repair dont crack.
you can also use stainless steel screen for your bridge. it can be cut/contoured to the shape you need, melted in with a wood burner.
these tail light lenses had 5 out of 6 screw holes cracked. they now have studs. first i melted in the screen pieces with a wood burner. then i used a tap to lightly make threads for my stud. i cut the studs to 1" , fit them in the holes, and used a soldering gun to get them hot to the point where they mated to the plastic. i had to make sure it slid into my housing properly, remelted any studs that were canted so they would fit. new tail light lenses would have cost $399 for a set of 2
