Vehicle cabin sidewall-to-floor coupling assembly and method of assembly

A system comprising:

• a floor assembly;
• a sidewall assembly;
• and
• an assembly comprising:
• a floor coupling structure comprising a floor interface portion and a sidewall interface portion that extends transversely relative to the floor interface portion, wherein the floor interface portion directly attaches the floor coupling structure to the floor assembly, wherein the floor interface portion is flat and attaches to and overlays a portion of a floor panel of the floor assembly;
• a sidewall coupling structure having at least one friction-fit portion and a sidewall attachment section, wherein the sidewall interface portion projects upwardly from the floor interface portion, wherein the sidewall attachment section couples the sidewall coupling structure to the sidewall assembly, and wherein the at least one friction-fit portion couples to the sidewall interface portion of the floor coupling structure;
• and
• a transition portion that connects the floor interface portion to the sidewall interface portion.