After getting my zed home I noticed that both fog lights were swimming in water which seems to be a common problem, I thought ventilation might cure the symptom (if not the cause) so drilled a couple of small holes along the bottom face of the light

The marks that are still visible are just soiling from the dried out lakes that existed before...
Not so visible from the front

If you have wet fogs it's worth doing IMHO

The marks that are still visible are just soiling from the dried out lakes that existed before...
Not so visible from the front

If you have wet fogs it's worth doing IMHO