I've certainly had my fair share of language vomited at me because some people somehow feel threatened by a cute and cuddly car made by French people. Just go to any news story involving a smart with comments to learn what angry people think of the car. I think in times like these when people are not sure how gas changes will or will not change, and how our lives could change as a result might feel threatened by something so radical as a tiny, fuel-efficient car. If people are spitting on your car they must feel very threatened about something.
Just don't take it personally. Most people I've seen love the car. If they don't just smile and wave at them. I sometimes put my bottom lip out and motion "yea, its small" with my hands, and it often changes the reaction to laughter. Poke a bit of fun at yourself and it might turn them around. If you're worried about vandalism or road range, maybe put an American flag on the car or show some from-the-heart patriotism in your own way. It might make the car less construed as "un-American" to some. Or you could get a humorus bumper sticker that says something like or "freedom to drive something FUN", "Shrinkage May Occur when Wet", "We gotta fight for our right to smaaartay" or "They'll give me the other half when I pay it off"
