A small nut and bolt. Use a blunt drill bit (I seem to have lots of those) to drill the plastic, with hign
RPM but slow progress, so it is really melting the hole rather than drilling and cracking. Then finish off with the
adhesive of your choice, 5200 being a reasonable possibility. Then the load is off the
adhesive.
If that option does not appeal to you, sand or drill holes in the plastic where the latch will be mounted, so the adhesive you choose has more surface to grip.