I had a conversation with a cyclist who grew up in one of those "high crime neighborhoods" in St. Louis. He said that he received strange looks and comments when he visited his old neighborhood with a road bike attached to his car. He belonged; the bike did not. I suspect that more-than-casual cycling is a cultural oddity in some areas. I'm not sure that walking would garner the same reaction.
Whenever I see a bike in a car I assume the person has a lot of free time and therefore is somehow what well-off. Perhaps people were subconsciously judging his wealth?