You know how your eyes can sometimes get things wrong? For example, you can see a mirage of an oasis when you are in the desert? Well, radar has failures like that. For example, in normal everyday driving conditions, like when you go over a pothole, someone passes through the lane in front of you, or you go under a bridge radar tends to hallucinate just like your eyes tend to hallucinate. It tells you things that aren't true about the observed reality.
The most famous story about radar that I know is the time that ignoring it prevented the death of humanity. There was an illusion of a nuclear launch by the United States on Russia. The officer didn't believe the radar and so didn't launch nuclear weapons in retaliation.
If you were combining radar with your eyes while driving, rather than combining it with hearing, you would have times like that - times where you recognized that the sensor was wrong and you were forced to ignore it. Or you would die. And others might very well die with you.
IMO we do - try driving with the windows on both sides down a crack. Your brain synthesizes traffic noise into your mental model. You can be aware of traffic near you without being able to see it.