The generally available car will have cold-gas thrusters which boost acceleration but is nothing like what was demo'd.
The flying trim will never be sold to general consumers. Even the rear-thruster trim is currently listed at a $250,000 pre-order fee, which is a deposit for a fraction of the full cost of the car. Final cost will be over $1M. Any of the thruster variants will be extremely rare; like, the one guy in your city that has one will show it off at car shows twice a year, McLaren P1, level of rare.
Plenty of ways to maim/kill people in traditional cars already and I doubt this will be the most common one in roadsters.