So, i know this is a bit off topic but ive noticed this now that im spending much more time on the road in my new career. Cars going round corners and spot/fog light comes on on one side only then goes back out after straightening out. Never noticed it before but ive noticed dozens in the last few weeks. has anyone else? what causes this?
Its not a fault. Plenty of newer cars do it, you steer in a given direction and the fog light on that side comes on. Goes off when you are steering straight again.
ah, i was beginning to think that might be the case. not sure i understand the real need for it mind yu
Presumably to provide additional visibility on the inside of the turn and direction of travel.
But since the highway code (rule 236) says fog lights must not be used except when visibility is seriously reduced (100 metres), isn’t it illegal to use them simply to aid going round corners? The rationale that they dazzle other road users remains the case.
DELETE
Visibility issue yesterday pulling out of a layby, heavy rain waited for a lorry and car looked, all clear pulls out, next thing a wagon with no lights on appears out the mist and starts flashing at me! If he had his lights on I would have seen him and waited!! 
I believe these lights are known as “driving lights”. I’ve got them and they’re no use to man nor beast.
Pete 
I’ve always have to be careful with the daytime run lights on my car. They’re so ■■■■ bright when I first had the car on 2 occasions I forgot to put the main lights on, and they’re even bloody brighter. God bless Xenons!
a little off the OP’s subject but people need to stop putting on fog lights at night “because they cant see 100m”
ITS NIGHT NO ONE CAN SEE 100m AT NIGHT!! 
The worst one I have seen recently is the guy that was determined he wanted day time run lights as everyone else has them so he stuck his fog lights on to look cool. Hate it when people do that
To be considered as fog lamps, lamps must be fitted and operated as a pair, equally spaced from the centre of the vehicle. Having one bulb u/s would still count as being operated as a pair! Using one lamp as a part of an adaptive cornering lighting system wouldn’t be considered as a fog lamp, under the road vehicle lighting reg’s.
Unlike the clowns who drive around with their side lights and fog lamps on to look ‘cool’.
Interesting insight into the rules, thanks. Completely illogical, mind you…
So switching your fog lights on as a pair is illegal because they cause dazzle for other road users, but switching on only one independently of the other is permitted and must presumably therefore not represent a dazzle hazard? It’s the same lamp isn’t it? 
ORC:
Interesting insight into the rules, thanks. Completely illogical, mind you…So switching your fog lights on as a pair is illegal because they cause dazzle for other road users, but switching on only one independently of the other is permitted and must presumably therefore not represent a dazzle hazard? It’s the same lamp isn’t it?
They’re not fog lights, they are just fitted in a similar position on certain cars.
My wife’s car has bi-xenon headlights (so main and dipped beam are emitted from the same unit, and changed by a moving shutter) with the headlights as the outer light of set of quad lights.
The inner units have Fresnel lenses so they aim at 45° and only light up below 25mph when you indicate in that direction.
Great at night.
The DRLs aren’t an issue either as the headlights switch on automatically.