Pay attention to how you use your feet when driving. If you drive an automatic most of the work is done with your right foot. What I want you to pay attention to is how you are using that foot. Are you using the whole foot or just part of it? Do your knees fall out to the sides when you drive? If that is the case then you are losing the support of your core and shortening the inside line of your leg. Even when you are driving you can engage your core. Try to make contact with your whole foot in the one that is working the pedals and resting while keeping the knees inline with your hips. If you are able to raise your seat so there is a slight downward angle of your thigh. Lastly make sure to find your seat bones so that your upper body has support.
Lauren Gee Certified Rolfer™
Rolfing ® Structural Integration Longmont and Northern Colorado