And have you heard about VASIMIR and Ion engines? VASIMIR is still being developed but the Ion engine is currently in use. And from what I have heard may even be installed on the next shuttle. Though it would still have to use chemical rockets initially to break free from the Earth. A good Ion engine could make the trip to mars in just 39 days....with far less fuel consumption than what the current shuttle uses if it were to go the same distance. (imagine how quick it would be to go to the moon. You could literally go there and be back in time for dinner.)
As far as inhabiting Mars perhaps I did word that wrong. I was thinking of dome colonies. But who knows. One day we might be able to terraform it.
I have a saying, nothing is impossible if you have the knowledge and resources to do it. And that is part of what NASA is about..gaining the knowledge.
BTW why use an example of something that works? Just because you think it would be stupid to allow the "average citizen" to use one? We have the technology to input a destination and have jumbo jets fly themselves. Why could that technology not be applied to flying cars? Granted the hard part would be take off and landing but I'm sure something will eventually be worked out in that department.