The DRL does not sense light as an automatic headlight system would, it only ensures the headlights are on at dimmed intensity when the ignition is on and the vehicle is moving above aprox. 3mph.
There is no location that I can find in the wiring diagram that will give a perfect 12v signal, it will be close, but not perfect.
Since our lights are positive ground, you will need to invert either the low beam, high beam, or both (depending on if you want your circuit to be activated with only one or the other or both high and low beams) wires on your headlamps.
To do this, you need to take a relay and connect pin 86 to fused battery positive, and pin 85 to either the high beam wire or low beam wire NOT BOTH. (unless you use two diodes 'pointing' towards the headlamp wires, not the relay. Make sure they can handle 12v at about 6W) Then connect terminal 30 to battery positive. Terminal 87 will only power on 12V if the selected beam (high or low, or both if diodes are used) is on.
If you don't want to use diodes, but want the circuit to be powered with both low and high beams, you will need two relays, one with terminal 85 connected to the low beam wire, and the other connected to the high beam wire. Terminal 86 for both relays can be attached to the same fused location. Terminal 30 on both relays can be connected to the same fuse. Terminal 87 on both relays need to be spliced together then sent to your circuit.
Here is a download link to the relevant section of the wiring diagrams
https://1drv.ms/b/s!AivLG2b81LJSi5MyhrouokMMFYejZQ