I had a play around with a multimeter at the weekend. The black wire is also a switched live on mine (no surprise, as we have the same car
) but I could have sworn it was at position 1 - either way, it's the black wire.
The reason for looking though, was to see if there was an unused wire which was a switched live until the headlamps were on at which point it killed the current to it i.e. DRLs for the daylight as I think was mentioned as standard with other cars....well, I didn't find one!
I wasn't expecting to find anything as the sidelights can be already activated as DRLs through VCDS so no need for another DRL circuit. Simply wiring into black wire as you have done is good enough for me anyway.
EDIT:
Err, I noticed this from the ebay ad for the DRLs...
Notes:-
Yellow wire to connect to the headlight positive side to turn DRL off when main dipped beam lights are truned on like most Audi vehicles if required (not compulsory), red is positive and black ground, easy DIY fitment. So I'll shut-up now and stop pi$$ing around with multimeters
How did you get on Carl - did you figure a way to tie them into the dusk sensor so they're literally DRL's and turn themselves off when the Xenons come on?
From above, keep them on auto and splice the yellow in to the main headlamp wire, I guess.