There is a lot of confusion about this subject. The
driving lights fitted to Aus delivered cars according to law are wired to only come on with the high beam.
And why would you ever want them to come on independently anyway, because the beam is designed to illuminate the road a long way ahead and would dazzle oncoming drivers in a low beam situation if they were switched on. Much better to have them switch off automatically if the low beams are on because you would forget.
The genuine Toyota clear lens type
fog lights that are fitted to some JDM cars a look exactly the same externally as the
driving lights fitted to Aus del cars, but have a different reflector designed to focus low and wide.
If you fitted those you would
definitely not want them on with the high beam in fog so they should be wired independently.
BTW, in Victoria it is also illegal to have
fog lights on during the day unless you are driving in fog.