I went out and checked the battery and horn, lights, etc...they all worked fine. So it's not the battery. My mechanic said the ring gear was bad when I got the oil changed a month ago. My main question is whether there is a way to start the car? Is there a way to move the car in gear? What about moving it backward?? is that ok?

And how much is it approx. to change the ring gear? And would I need a new starter as well?? Total approx. cost?

Thank you,
Matt