While current research in human-vehicle interaction tends to focus mainly on the safety driver in Level 3 autonomy, the advent of Level 4 (and even 5) fully autonomous vehicles will shift this focus from driver to passenger. During the transition phase from partial to full autonomy, passengers are likely to be apprehensive about their safety in a self-driving car. Provisions must therefore be made to minimize passenger anxiety at all times. This work explores current trends in human-vehicle interaction with a directed focus on the passenger, while posing questions that serve to tackle the problem of passenger comfort in fully autonomous vehicles.