Until we get to the full (and safe) self-driving car, safety technology in cars will be big sells, in my opinion and one of the biggies is stopping those impaired by alcohol / marijuana from operating a vehicle.
Currently the tech is pushed from the state from the courts. You get a drunk driving ticket and you will have your car set to test you and pass before the engine comes on. But if the tech can actually and passively collect and analyze the breath correctly, then it could be phased into cars.
Right now though, we are not there yet as this NPR article points out. I do think the time will come when it is standard and when that time comes, I also hope that having a bajillion devices lit up in the drivers view will also have a fix. The other DD (distracted driving) is a big problem too.