With the heater on and fan running there is a faint odor of exhaust when sitting still. This odor is unnoticeable when moving. I have suspected vehicles in front of me emitting fumes that are sucked in by the fresh air cowling, but it makes no difference whether I am behind someone or completely alone.
On Monday I had the car at the dealer for annual safety inspection and mentioned the odor. The mechanic said I had no exhaust leaks since it would be heard rather than smelled.
I have not noticed any leaks or radiator fluid loss. There is no smoke emitted from the engine compartment. Is there anything else to check other than my head?