AP/AD Patrol?

Hey guys, so I’ve noticed a couple mornings on my commute (early, around 5:30am) a vehicle that looks like an HPD Cruiser but says “AD Patrol” on the side (I can’t remember if it’s AD or AP actually).

I’ve googled it a few times and cannot seem to figure out what this is. Does anyone know? I was thinking maybe “After Dark” Patrol but I’ve never heard of such a thing.