Spend some time generating calm, peaceful thoughts. If you've been following along with my tip series, you could do the Happy Safe Place, or bilateral stimulation, or heart-centered breathing, or belly breathing. Whatever does it for you, to get into an awesome state of calm and relaxation. Spend enough time on it that you get the calm going really strong and peaceful and deep.
Then, pool that calm into your hands. Maybe it even has a color, or a sense of cool, or tinging. Then in your mind's eye (or in real life if you're sitting in your car) send that peace into the steering wheel of your car. Fill it up big and bright with peace and calm and relaxation, and give yourself the suggestion that every time you put your hands on that steering wheel, your stress will drain away and you'll feel totally relaxed and alert, able to pay attention to anything that needs attention.