Glad to hear that you're recovering well! Thank you for sharing your experience with us. It's disappointing to hear that the interface you purchased has several bugs and crashes frequently. In my opinion, it's not unreasonable to expect a device that costs $350+ to operate flawlessly without any bugs, especially when it is intended for use in a car where music and navigation are important.
If the device fails to deliver that, the company is responsible for finding a solution. They should either refund a significant portion of your money while allowing you to keep the interface or provide a full refund and cover the return shipping costs. If I were you, I would contact PayPal customer support and explain your situation over the phone, as it may increase your chances of getting a favourable resolution.
I was in contact with a woman named: 'Sandy' from the Hualingan company through WeChat. She has been very pleasant to talk to. When I asked her if the audio cuts out when reversing, she assured me that it would not. It's strange that they would lie about it as your experience says otherwise. I trust your experience more than their word.
Initially, I planned to purchase one interface to try it out in my car. If it worked well, I would have bought ten more as I know people that would love to have fullscreen CarPlay in their cars. However, now that I have heard your complete review, I have informed Hualingan that I am no longer interested in purchasing the android interface.
If you are ever in the Netherlands, feel free to shoot me a PM. I would love to treat you to a beer in appreciation of your honest review, which saved us all money and headaches.