Dreams are fascinating. I look at the emotions they contain and symbolism/metaphors. So, what did the car do? It ran away without you. A sense of lack of control about circumstances or your moods? The best person to work out what it all means, of course, is you.

I love Sandra's suggestion in her comment about a practice for emotions.

If I have a challenging mood, I accept it these days and ask it to pull up a chair. I offer it kind self-talk and it melts (over time). Maybe this will work for you.