Lack of accessible transport for People with Disabilities (PwDs) negatively impacts access to work, social inclusion, and healthcare leading to adverse effects on overall well-being. The absence of access to autonomous mobility exacerbates these issues, presenting barriers for inclusion. Previous studies have provided important recommendations and while these represent important steps in the right direction, they often lack detailed principles to support design of accessible AVs. To address this gap a multi-study research, with the overarching aim to develop design principles for accessible AVs, was initiated by the Queensland Government Department of Transport and Main Roads (TMR) and conducted by Queensland University of Technology (QUT). This paper reports on an early study employing focus groups and workshops with five domain experts. Thematic coding resulted in five major themes: COMMUNICATION, STRESS, INDEPENDENCE, SAFETY, and INTERFACE, each consisting of multiple interconnected topics that contribute towards initial design principles. Later steps will involve developing an accessible AV concept using these initial principles. The concept will be refined into a prototype and tested with PwDs and reviewed by domain experts. By incorporating purposeful design principles it is anticipated that AVs will become more widely accessible alleviating barriers to freedom of movement for all.