Losing a dog in fog is highly unthinkable. Back in 1994 I witnessed several dogs invade a medley of mist. Yet I was STILL able to establish their presence with just a meager bit of common sense. I understand this is not the case in Britain. British fog is so substantial that you cannot tell where the fog ends and where YOU begin. Do NOT go to Britain and if you must, wear a bright orange sweater, goodnight.
If you personally import a car - eg: there's some new Mustangs around here - you have to get a rear high intensity (fog) light fitted before you can get it registered.