Extensor Rotator: Sitting continuously for long hours, keep the hip joint locked at 90 degree, leading to tightening & thereby shortening of external rotator. In addition, running being a repetitive movement makes it further stiff. Just sitting in this position in which your legs are folded will help work on your external rotator.
Quadriceps: Sitting simply in Vajrasana will stretch your quadriceps
Quadriceps, Toes, Metatarsals, Arch: Sit in Vajrasana. Tuck your toes and keep pressing your toes against the car seat. This will help stretch toes, metatarshals as well as the arch of the foot and bring relief to those areas after a long run along with your quadriceps.
IT Band: The left knee is bent and the left heel is close to right hip. The right knee is stacked at the top of the left knee. Press the right knee over the left. This will not only stretch your IT band but at the same time release lot of tension from the legs.
Hamstrings: Just stretching your legs in this manner will help stretch your hamstrings. Maintain the stretch for sometime, then slide your heels out and toes in, hold for few seconds, then slide your heels in and your toes out, hold for few seconds and repeat the process. This will give good stretch to your calves.
Hamstrings: Bend forward in this posture as much as possible as per your comfort and you will feel deep stretch in your hamstrings.