I think this is about you not trusting her. If she is driving you in the car, then she is in control... the car represents you (IMO). But she was drunk, which to me could mean you might see her as less than reliable and maybe not totally aware of what she's doing, the power she has over you, etc. She doesn't even get in the right seat, then corrects and gets in the drivers seat... I'm sure that's scary as well, who wants to be driven by a drunk driver!

This is interesting though, I also recently had a dream about being in a car with my therapist where he was driving. My therapist wasn't drunk though... in my dream I reached out and put my hand on his hand without thinking about it, then realized I was touching him and squeezed his hand awkwardly and then couldn't take my hand away... we got out of the car at some party and I started hugging him, we went from hugging standing up to hugging lying down somehow (like dream magic) it was such an awesome dream, way better than anything that's happened in my real life recently!