Radar is well proven, why has it been ignored by Tesla ?
My Audi is now more than five years old, and it has a driving assistance system which the manufacturer does not market as an "Autopilot", rather they call it Adaptive Cruise Control. It relies mainly on two Radar antennas mounted at the front of the car beneath the headlights, in addition it leverages a front-looking camera which keeps track of the road markings - the radar adapts to that camera view and looks along the current lane which prevents unnecessary braking when there is a road bend and another car on a neighboring lane.
The system is very reliable and really convenient when being stuck in a stop-and-go traffic jam, also helps greatly during normal traffic situations, for instance when another driver unexpectedly pulls over into my lane. The system reacts properly also to smaller vehicles on the road (eg. bicycles) and no doubt would detect a big truck crossing the lane ahead. However, I still keep watching the street rather than watching Harry Potter videos while driving.
I simply can't understand why Tesla did not do proper market research and did not find out how experienced car makers are helping their customers with advanced car assistance systems. Again, my car is more than five years old. How come that Tesla started to build radar antennas into their cars only as late as 2014, and only now starts to take radar somewhat more serious ?