A parked car is one of the few places most people are properly alone during the day, waiting for a meeting, a collection, an appointment. It is also an easy stretch of time to spend scrolling instead of resting. This short meditation is built for exactly that window.
The same brief-practice research referenced on the Three Minute Reset page applies here: short, regularly repeated meditation is not an inferior substitute for longer sessions, it is a legitimate practice in its own right, and one that fits into moments most people already have.
Keep your eyes open if closing them feels unsafe or unwise in a parked car in public. Most of this practice works with eyes open, attention simply resting on your breath and the sounds around you. If the waiting you do most often is the school pickup line, there is a breathing pattern written for exactly that.