Research shows that wearing your mask, and opening the front passenger window, and the window behind the driver seat helps to reduce the spread of the novel coronavirus in your vehicle. See this NY Times article.
I commute to San Marcos Outlets for work. My schedule is a little bit all over the place. Most days I am there by 9:30 a.m. and leave about 5:30 p.m. looking for someone to car with on some days just to save gas and vehicle maintenance.