The word idle literally means to stall or hesitate in some way, and so seeing this manifest in some way in your dream implies the literal interpretation. You may see a general sense of laziness in your dream, either within you or from those around you. You may be in an actual vehicle that is idling in your dream, or you may simply be idle yourself in your dream, flitting lazily from one thing to another in your dream world. Generally speaking, a sense of idleness in your dream is a symbol of boredom, and your dream is pointing you to your lack of initiative and drive.
Are you in the wrong relationship? The wrong job? Seeing this in your dream is a suggestion that your life could be moving forward, but for some reason it isn’t. Sometimes this is a good thing. Sometimes you need to stall a moment before pressing forward. Idling in a storm can be a respite for example, sometimes we all just need to pull off to the side of the road and take that call, or think things through a little before we make a final decision. If this symbol occurs in your dream, your dream is either telling you to make that call, or make that stop and think things through.