Fog lights

[AntMB]

The fog lights on my wagon have sort of lost the reflective layer inside them. Is there a successful refurbishment spray for inside it if I were to take them apart? Or is replacement best?

 

[LostKiwi]

Replacement is the only viable option.
The surface us a very thin highly reflective coating which needs to be precisely applied to prevent poor beam pattern and dazzling other drivers.