Looks like each cam has its own square-shaped IR illuminator located behind it and oriented for the cam.
Maybe an undercover LEO-operated vehicle (not very inconspicuous if so).
Maybe those are some kind of radar (not IR) -- otherwise I want to add another guess: Mobile License Plate recognition (like for violations or finding stolen cars etc)
I'm thinking that because that style camera I wouldn't think would be wide enough field of view to give 360 degree view, plus there are no cameras mounted pointing directly left & right of the midline. But if you were driving up and down rows of cars (on both sides of a road), this configuration would be basically perfect.