these things are quite flimsy.
I'd recommend to replace them with visors from other cars,
e.g. from a BMW Z3:
https://www.the-t-bar.com/forum/68-the-t-bar/89870-z3-sun-visors#127452
or Alfa Spider/GTV:
https://www.the-t-bar.com/forum/9-mgf-tf-pitstop/42279-sun-visor-alternative#42345
as ever,
Rob
http://www.reliant-scimitar.weebly.com/