Modern cars are likened more to robots or computers, rather than horseless carriages, wherein you simply find a different fuel source and everything else stays unchanged. Example: Think of what capabilities the computer will have in say, 20yrs. The truth is, we could actually do those things now, but the cost is prohibitive, both to the manufacturers and hence the consumer. It's the same with cars. Change takes time, and at least Hybrids are starting to get the oil monkey off the public's back, however disingenuous the idea.
Off-topic, I think that the best solution is to find a way to fuel our locomotion by combining garbage and human waste. Kill two birds with one stone. Ideally they could apply a refining process to kill the odor and pollutants. That's where we should be in a century.
