I usually offer up fun and money. I like to ride so much that I was only starting my car a couple times a week. It was breaking down to $50 each time just to turn the key, so, I might as well ride everywhere, or rent a car once in a while. Going car-less might mean $500-$1000 a month in the bank, which should at least be worth a second glance.
If they are interested, I might tell them how I lost 100 pounds, and got off my high blood pressure meds. That's why I started riding, but I kept it up for the fun, and turned in the car for the cash.
Don't fret about others' reactions and perceptions. The car is too much a part of their lifestyle, and you'll rarely break through. You might as well ask them to eat bugs or live in a tree.
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Campione Del Mondo Immaginario