Side guidance reverse lights

For anyone that doesnt know the term its the lights on the side that go on when you put the car in reverse. They should light the sides of the car...
Mine has the space for them (the rear end of the front blinkers) but theres no light installed in there. Cables should be hidden somewhere in the wiring loom.
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(bad camera phone picture...)
Got a few questions about these....
1: Are they still used on production cars, or is it an optional addon
2: If they are installed, what light bulb goes in them (5W or 21W)
for people who have them: do they help or is it just for show
Mine has the space for them (the rear end of the front blinkers) but theres no light installed in there. Cables should be hidden somewhere in the wiring loom.
.jpg)
(bad camera phone picture...)
Got a few questions about these....
1: Are they still used on production cars, or is it an optional addon
2: If they are installed, what light bulb goes in them (5W or 21W)
for people who have them: do they help or is it just for show