YOU SIMPLY HAVE TO TALK TO HER!!!
My parents have quit a couple of months before me.
I've stopped smoking in the kitchen (we used to smoke only there), and I tried to cut down as much as I could in front of them.
In the end I've noticed that eventually I have cut down too. And also I've noticed how much easier it is to quit when you ged used to not smoking at home.
Make a compromise, ask her if she can smoke in just one room, I can't imagine you have house so huge it would be a problem.
Or a couple of rooms you don't use so much. You can always open the windows when you come inside.
It is her house. Fine. But you live there too.
And as for the car... Explain to her how much it bothers you. If it doesen't help open the windows.
An one more thing. If she won't compromise about the house beacuse it is hers you don't have to about the car.
Make a point.
She can complain a bit, but whats the worst that can happen to her? She won't smoke a couple. She can live with that.
We all can.