Identifying usable and intuitive in¬teraction methods for novel display technologies, in settings where multiple interaction modes and devices can be used simultaneously (such as the car), remains a challenge for developers and user interface designers. The process can become even more complex when the target hardware is still in prototype stages of development and does not support usability tests in early design iterations. Using an affordance-guided user-centered elicitation survey with non-expert participants, we researched intuitive unimodal gaze interaction concepts to complete a series of interaction tasks with a 3D UI in a HoloLens 2 emulation of a 3D holographic passenger display inside a car.