I'm not sure of the lighting regs in the US but in UK/Euroland it goes something like this......and how Hella anticipate/designed their use.
Basically the way the light should be used is on all the time once the ignition is switched on and off once the position/side lights are switched on....
I have HID headlights and LED sidelight bulbs so I think if I ever get these I'd wire them up to go off only when the main headlight are used, in otherwards keep them on with the sidelights...
There is no dimming function with these lights, just on or off. They look good, nice job