1. My profesor works at CEARN where they produce antimatter...he's one of the lead scientists there, so I know what I'm talking about. You spend MORE energy to create antimatter then you get from a mater-antimatter reaction. Why do you think they only produce small ammounts of it for study purposes if it ralyl is such a efficient energy source...
2. You're perfectly OK with a concept of society where every citizen has the means to blow up the city? And you really think a society like that could exist? Just Bob tinkering in his garage and making a mistake could level the block, let alone if people would activly try to make things go boom.
First thing's first, a nuclear reactor is not a nuclear bomb(this would be the third time told). One releases energy all at once, another doesn't. Now if nuclear powered cars is such a bad thing then i guess the nuclear power plant would be attacked next. Nuclear power plants, great way to produce energy with the only waste being steam. Now if i could have that for my car that'd be kickass. But, nuclear power for cars is highly over kill for the energy source of a car in the first place. If it did happen, then that be one crazy car, that probably doesn't have plans on being fueled in the next 10 years or so (wouldn't be good for the economy either).
Plus, i'm not thinking a nuclear reactor for a car would need to be that big. Nuclear reactors can pump out a lot of power, so that means you could probably make a tiny reactor that could spit out a lot of energy as well. I don't see why a nuclear reactor couldn't be something small enough to fit in a car, or even a motorcycle.