Turns out, we were right, it was being used by gun runners, and the police found weapons in it. We're hoping this means that the car is in good enough repair to drive it home and use it. Also hoping that they will actually release the car back to us and not try to tie it up in some kind "evidence for the prosector" manner.
Will find out soon...
* When I was texting a friend about the car situation, the auto-correct helpfully changed "gun" to "fun." I guess writing about gun runners is not an everyday occurence. Many more fun runners in the world. :P