This plate lamp looks terrible. It needs cleaning!
Step 1: Removal.
Just 2 screws to be removed here. See the rust inside? Nasty.
Step 2: Cleaning.
Using engine degreaser I cleaned the lens. Then I dried thoroughly. Now it's super clear!
Step 3: The Culprit.
Water ingress caused this led to rust. I replaced with a new led.
Step 4: Completion.
I reassembled the lamp with an dose of silicone gasket maker to ensure weather protection. Now the license plate will be well lit!