The fire was in the garage. Why does the far wing of my West Bloomfield home smell of smoke?

Because the house breathed it there. With the HVAC running, return air pulled smoke laden air from the garage side and delivered it, diluted but real, to every room that zone serves, and soot films form wherever the air went, heaviest near supplies and on cool surfaces. The verdict is empirical, not geographic: surfaces are tested in the far wing, ducts are read, and the scope includes what the tests condemn and verifies what they clear. Distance from the flames is not evidence in a forced air house; the air pathway is. That is why the first call asks which zones ran, and why shutting the system down is the first instruction after any fire here.