Engineering as a field is dominated by toxic masculinity, heteronormativity, whiteness, and cisnormativity. There is a dearth of research about transgender and gender nonconforming (TGNC) student experiences in engineering, and much of the available research on TGNC STEM student lives does not account for the nuanced intersections of marginalized identities that can affect a student's performance and sense of belonging in engineering or larger STEM environments. In addition, STEM-related research into marginalized populations' experiences is often done without the use of feminist, queer, trans, and anti-racist research methodologies that consider power imbalances between the researcher and the participant and the implications of conducting research on and with underrepresented populations. This study addresses these research gaps. We used critical collaborative ethnographic site visits to center TGNC positionality and community-centered research ethics. The four-day site visits presented here involved two mechanical engineering students at a prestigious private university on the East Coast of the United States. Activities included formal semi-structured interviews as well as less formal interactions with each participant, such as attending classes, visiting important campus and community spaces, and hanging out with the participants' friend/peer groups. The visiting researcher also explored the college campus and the broader community on his own to more deeply understand the politics and context of the local environment. As predicted by significant findings from previous phases of this research, the uniqueness of each student's identity, location, political worldview, and support system significantly impacted their educational paths in engineering. The two TGNC student participants, both with multiple intersecting marginalized identities, had incredibly different experiences in the same mechanical engineering program, leading one participant to resounding success and the other to leave STEM altogether. The findings from this critical collaborative ethnographic site visit suggest that barriers to success and a sense of belonging for TGNC students in engineering must be considered through the use of intersectional critical theories.