Totally sucks, but if that helps...
It happened to a neighbor, same kind of deal, older unremarkable car. Two days later it was found parked some miles away, tank empty, all personal gewgaws gone, but unharmed. Police told her that people steal these kind of anonymous cars for drug runs. Use them just one or two times, then abandon. They take off personal gewgaws because they want them to look as anonymous and impersonal as possible, so if anyone sees them all they can say is "blue Corolla" or something, and even if a bystander gets a license plate number the vehicle turns out to belong to some innocent person.
So, hopefully, something like that, not cool having your car used that way but it least she got it back with no real harm. Best to you. Be sure to file police report.