How Tesla Model X can be about car-2-car transit at speed

I have realized that ones we have self-driving cars, the next step will be to switch between cars at speed. This could drastically reduce prices by higher car utilization, lower the number of cars on the highway, plus increase travel speed without the need for stops. Could this already be realized with Model X? It seems so. The Wing-doors can be opened more than 45degrees (not possible now due to SW) enabling two cars to drive up close to each other on the highway and open the doors at speed. It's also easy to remove the front arm-rest so all 6 people can exit through the same door. If this is part of Musk's, the other car producers will already be behind when they all have self-driving cars on the highway.