My car does this too!!! Its a 52 dynamique, bought it accident dammaged from a lad at work who hadnt claimed on it.
It had been sitting a while so battery and altenator were buggered, my electrics came on when i was driving but went of when i came to stop lol.
Anyways on the off chance in the first 3 days before i got it sorted it decided to work all the electrics were fine, front fogs and rears and h/ls and everything.
Next day it went to auto electricians, since then fogs havent worked =(.
I noticed few days ago that one bulb wasnt fitted so went to local parts seller n they wanted £10 per bulb!!!
So made a trip to eBay lane n got full hid rep bulbs for full front end for £10
.... But still no work =(
P.S anyone know anyone who is cheap at fixing dints and spraying in north-east?