I'm working on a couple of vehicles to make use of the EVCS beta. This one is the vapid and currently you can control the pushbar and the lightbar, so you can have three different types of police car (general patrol, highway patrol and unmarked) all in the one slot, and switch things up to your liking using the EVCS mod.
I'm also testing a tow-truck using the mod so you can have an amber lightbar, seperately controlled amber lights on the tray, and the ability to deploy/retract a ramp and to put up or put down barriers around the tray.
Obviously as EVCS progresses, giving us more control over the vehicle, I can expand these concepts further.