I reckon that's an essential mod 66FBK, front and back. In strong daylight people are having a good squizz at the car and don't seem to pick up the white indicators at the front, or the red ones in the tail lights at the back.
We forget that most drivers under about 60 would never have seen white or red indicators.
I fitted upgraded H4 Halogen headlights with internal parking lights, so I could then use the small lower lights just for the front indicators, with amber lens. Deleted the reversing lights and wired them as the rear indicators, again with amber lenses. It's a good idea to fit headlight relays for these more powerful headlights.
So no screeches of brakes, rude names or one fingered salutes (other than from the missus) since then. :(