The built environment remains a persistent accessibility challenge for people with mobility impairments. Whilst platforms to report these inaccessible locations exist, the underlying documentation processes are verbose, time-consuming and fail to effectively communicate the barrier at hand. We propose WheelieMap, a platform which uses the motion of manual wheelchair users to support the identification and documentation of potentially problematic locations. WheelieMap captures and segments device video footage and GPS as evidence of the problematic space, which can then be shared with both other people with disabilities and the relevant authorities. We document the use of the WheelieMap prototype by both manual wheelchair users and planning experts through semi-structured interviews. The qualitative findings revealed this approach to be the most viable route for documenting inaccessibility, compared to the existing alternatives. We also offer guidance on how to design and develop similar community driven reporting and annotation systems in the accessibility setting.