Finally took my 2015 Kia Sorento to the dealer today because the radio and back-up camera screen haven't been working for a while. I was told the Radio Head Unit needs to be replaced and will cost $1,400+. I asked what all it controlled, because at that cost, I might prefer to live without the radio and screen, but I was given a vague answer about it being like the brain and controlling lots more than just the radio. Can someone please tell me what else the head unit controls, so I can decide whether or not to replace it? Are there other options for fixing this that aren't as expensive?