"RichToyBox" writes:

Many plastics are very susceptible to UV. Polyethylene becomes brittle, PVC
has UV inhibitors, like carbon black or titanium to prevent degradation, so
depending on the type of plastic, it could be seriously affected and split
or crack, allowing water to the bulb and the electrical connections.

Plexiglas isn't degraded by UV, it's used in roof panels.
Good thought though.