Car etiquette in the wet

Flooded roads this morning; drizzle to rain; dark, and cold. Yet the number of vehicles driving along with no form of side-lights (at the least) was shocking. I mean I'm in a bright red car, but try to spot a grey/silver or black car through the side-window when turning or worse yet through a side-window at the side-mirror when changing lane with both are spattered with rain-droplets.

All you can hope for is to catch movement as any sign that a vehicle is there and, as one is supposed to, slow down and take things a little easier.

In the same vein - the number of cars that think that just because their side of the road is washed out they have right-of-way in yours and, from the other perspective, the number of cars that hug the middle line despite the lack of puddles on their side when you're trying to skirt a puddle while staying on your own side of the road.

Mandatory re-testing every ten years? I'd say yes.