W204 C63 headlight + water = bad

[brisel]

Just had to replace the nearside headlight bulb & igniter at a non MB garage costing £530 after hitting deep water early one morning just before New Year. The expensive bits are underneath the light cluster, so are very vulnerable! There are a couple of grommets on the shields that can come away and let more water into the cavity but these were still in place.

Beyond not hitting standing water at all, what can I do to prevent this happening in future? This garage has another one to fix having done the same thing!