It is possible to do various types of yoga poses while either driving or parked, depending on the circumstances. Since cars aren’t designed for yoga practice, you might want to use props, such as yoga mat under your sitting bones! Also you can use the headrest to make sure your head isn’t reaching forward, straining your neck and shoulders.
One way to practice yoga in a car is to do spinal twists while turning to look behind you before backing out of a parking lot.
Just inhale, lengthen your spine, then exhale and twist, first in one direction from the bottom of the spine, pulling in your belly, and then in the opposite direction to be sure you are balanced.
Driving is also an ideal time to practice Lion Pose with sound, especially when your jaws have become tight with frustration.
At a red light or while in stopped traffic, open your jaw wide, stick out your tongue as far as possible, and make a loud noise. When you are out of breath, pause and see how you feel. Then repeat if necessary.
An especially good yoga exercise to help deal with road rage is a game of projecting ideas onto objects to gain increased insight into the true nature of the mind.
You can do this by imagining that every car you see is a manifestation of a thought. For example, when a car turns in front of you without signaling, you could tell yourself, That’s the thought I have of constantly changing my mind and not knowing exactly where to go.