A perfect phaser as depicted in Star Trek, on the other hand, would be an excellent non lethal weapon. It would have the incredible intimidation factor of seeing a huge motherfuckin' energy beam being fired at you, capable of completely disabling the perp, with the added bonus that he is extremely unlikely to have suffered any permanent damage at all.
Police have access to the next best thing - Tasers which essentially do the same as a phaser set on, "stun."
Flying Cars would be as safe as Helicopters and Planes are, once they get a viable technology mass produced, but I admit true "Delorean style" flying vehicles are not likely to appear in the next 40-50 years, except with very niche organizations (Police, airports, high end transportation?)
Boeing is supposidly working on anti-gravity technology for the US Defense Department. The flying car isn't happening until any such tech is not only declassified but also introduced comercially.
BTW to the original poster. If Boeing has actually tested anti-gravity technology successfully that would represent a qunatum leap in aviation technology. I wouldn't expect the defense dept however to declassify any such technology soon.
Boeing, the world's largest aircraft manufacturer says it is working on anti-gravity propulsion, which could revolutionize conventional aviation.
If the science underpinning the program can be made into reality, it will be the biggest thing to hit the aviation industry since the Wright Brothers.
"GRASP," or Gravity Research for Advanced Space Propulsion, was only recently reported in Jane's Defence Weekly, but the U.S. military may have had the technology for years.
The National Institute for Discovery Science (NIDS), based in Nevada, say that mysterious U.S. military craft using this kind of technology have been skirting the skies since the 1980s.
And NIDS is now calling for the military to unveil its secrets for commercial benefit.
Although no-one yet drives cars or flies commercial planes made from radar-avoiding, stealth bomber material, over the years there have been spin-offs that have had business applications.