In my opinion, it is necessary to have more than one set of lights on your surveillance vehicle for night-time pursuit.  Having more than one set of lights will allow you to change the vehicle’s appearance when pursuing a subject on streets with scarce traffic.
 
Adding fog lights is one of the easiest methods of changing a vehicle’s appearance. Alternatively, if you are using a pickup truck as your surveillance vehicle, you can also add a second pair of driving lights under the stock set to make your vehicle appear taller or shorter.
 
Also, please keep in mind that if you have daytime running lights (DRL) you need to pull the fuse or put in a kill switch. Conducting surveillance with DRL is just asking to get burned.
 
One last note, I have various surveillance vehicles including a newer model Mercedes SUV. When I choose a surveillance vehicle, I make sure the headlights look as generic as possible. If you purchase a vehicle with HID lights like on a Porsche or BMW, or with LED light strips for DRL, switch out the lights for generic looking lights – this will ultimately help you blend in and make it more difficult for you to be identified by the subject.