This is an idea that Marc suggested, though not exactly in the form I'm posting. One widely known problem with EMPs is that they're extremely disruptive and don't take much effort to use. At the same time, they don't take much effort to evade, which is as simple as getting out of the car (though this has become more limited recently).
Instead of having one wave (which, in reality, would be radioactive and each burst would cause players to mutate -- this isn't RL though) that instantly disables a car and locks it, Police Mavericks would have somewhat of a mounted gatling gun, which would have to be operated by a passenger. The passenger would have to use something like /c emp to "lock on" to a car. However, instead of instantly disabling the car, the car would gradually lose something like 100 HP every second, firing explosive shells in short bursts.
If the car reaches 0 HP due to damage from gatling guns, the engine would be killed as well as the car catching fire, rendering it completely inoperable. However, if the driver of the car manages to evade the Police Maverick like EMPs, the passenger would have to lock onto the car again.
The driver of the car would receive on message saying something similar to "Explosive shells are piercing the hood of your car."
Also like EMPs, the helicopter would have a limited number of bursts before having to restock, at which point the pilot of the helicopter would have to restock while in the helicopter. This gives them 25 explosive shells for use in a Police Maverick.