I was searching for a way to do the same exact thing to my 2013 370z, and I came across what seems to be a good solution, here is the link for a kit from ijdmtoy.com which enables the Daytime Running lights to be used in night time as well along with the normal headlights, and seems to be a very simple installation, didnt get it yet, please let me know what you think about this as I am trying to find out if there are any disadvantages for using it:
Day light Enable Kit:
Nissan 370Z LED Daytime Running Light Enable Kit with Parking Lights
Installation Guide:
Installation Guide for Nissan 370Z LED DRL Enable Kit
Cheers!