Just noticed on my Wife's 2013 there are no daytime running lights, that are always on even when headlights are switched off or on auto.......I was under the impression most, if not all newer cars were equipped....
If she just leaves the headlights on, they will default to delaying 30 seconds to turn off after you stop the car and then open the driver's door. You can change that to 60 or 90 seconds or turn off the delay to get 0 seconds. http://www.toyota.com/t3Portal/document/om/OM47674U/pdf/sec_06-02.pdf (page 3 of the PDF, page 525 of the manual) The light sensor on the dash still controls dash lighting on the v, so you do not need to mess with that.
Some US versions have the ability to choose to have them on or off... Mine I can program on or off, Prius C has it on the stalk DRL off