I have run into two issues with the sensors:
1. At a stop light, sunny California + clean car, the front proximity sensors beep at random. This happens once or twice a week. Dealer could not find any issue with the sensors. My thinking is the ultrasonic sensors get triggered by the exhaust from the car in front of me or by wind. In any case, this should be a simple software update to make them less sensitive.
2. All safety systems went offline for three days. Then it magically fixed itself the day before the dealer appointment.
#1 is annoying, especially when on the phone or listening to music. #2 is a major issue in my opinion because I don't trust the car anymore.
What does not help: the service at the dealer is HORRIBLE. Service advisors are complete morons. I know more about this car than they do. Mechanics are sloppy and filthy and you can clearly see it on the white interior of my car...
I have/had cars from VW, Audi, MB, BMW and Subaru. Hyundai is by far the worst and I would not wish this type of service on anyone.