Have seen icing on cars as well, rare but not unknown....again, most cars have a thermostatically controlled air-blend-even if it's a simple bimetal-strip and pad over the "alternative" hot air pickup (Minis/metros/marinas etc.
Suzuki Swift I had suffered from Carb ice. It was brother's originally. He's an aircraft Engineer and recognised it immediately. Pulled off the most of the induction piping. It helped but on certain days you could go ten miles or so and it would stop, usually on motorways thus full power. You waited for the ice to melt and then drove on. If I wasn't a pilot or my brother wasn't an Engineer. It would have confused the hell out of us and we'd have spent a fortune in garages.
As it was we were amused.