A dog trainer I know who also boards dogs, told me off,well nicely, for pandering to my dog wimpering, its a case of tough love and his dogs, loads of them, all appeared pretty settled. My dogs are far too attatched to me as I am with them all the time too, I went into the forest with the car and had to drive it a few more yards to collect logs and my Labs got so worried they walked and even sat in front of my moving car...they were so confused, when its not hot, I often leave them in the car to go into shops and they are used to that, so yes, the car is a good place to get her used to you being away from her!