Similar tech has been done with cameras places in cars, but from a motorbike to monitor cars nearby would not be so easy, if the goal is to monitor the drivers

Similar tech has been done with cameras places in cars, but from a motorbike to monitor cars nearby would not be so easy, if the goal is to monitor the drivers face position (light reflection on glass is a major hurdle, i think). Perhaps it is possible to get the information based on car movement.