Hi - I had to check with my body shop and their reply was because the splitter didn't come with pre-drilled holes, they used what was already there on the car, so in essence no additional holes (apart from two - extreme left and right) were made.
No night-time pictures yet, but a small video of when I had a smaller much dimmer set of DRLs with a relay that switched them off on dipped beam:
http://www.youtube.com/watch?v=_JUpbk8jaqc