What kinds of techniques do autopilots of autonomous cars use? What kinds of techniques do autopilots of autonomous cars (e.g. the ones of Tesla) use? Do they use reinforcement learning? Which types of neural network architecture do they use?
They definitely don't use RL.

My guess is a mix of NN for segmentation, lidar, radar and how for perception.

Once object detection has been performed they use a trajectory generator and MPC.

There is an autonomous car class on Coursera that goes over this.