I am sorry this is happening to you. I, too, live in the sticks

and we do not even have an animal control in our county. Cops can only do so much and I don't think they take animal complaints to seriously unless someone gets hurt, and then its too late.
It is hard to talk to people like this because they seem to never be on the same page, being a drug user only makes your situation worse. I am glad she is paying to your car and it looks like actually taking legal action may be your only choice. Although it may cost you some, you have to ask what is your safety worth.
I still worry that bringing in other dogs may not work as planned. There is always the possibility of one of yours getting hurt...or worse.
Edited to say: I am just seeing she is not *longer* a drug user. Wanted to clear that up.