Have been unable to make any serious progress, but I did get a few things done.

I have enemies, but currently, no AI scripting to make them do anything, so they're more like crash dummies right now. Also got a couple HUD elements added in. Still need to add some kind of life bar, timer, and make the map (GPS) actually be a map.
I'm hoping the flashing lights on the justicars will be enough to convey their distance to the player, but I won't be able to tell until I've got some kind of AI working.
It's kind of sad how much time it took me to make the Justicar texture. Not being an artist, this stuff is super hard for me. I'm using the car from the Unity car tutorial, so I took the texture, and after a lot of dabbling, I managed to convert it into this:
