Just going to disagree with you there.
These are just your plain old RRVs, fly car in game.
You will find LOMs, locality operations managers, which is what I think you're referring to, who will use unmarked vehicles.
These unmarked vehicles carry everything barring drugs. They aren't therefore able to offer the full treating package of an RRV. Second to that an LOM is there to manage the scene, not treat. While I agree that they can, I feel like just giving them full ALS capability would be overstating their role and in at least this case, their equipment.
Yeah I just called them IRO’s as that was what was on the fleet list but the LOM’s in EEAS use Marked discoveries etc with specific Officer callsigns. I’m not sure if they have a unmarked fleet but they probably do as well.