The problem I found about the adaptors is that you can't charge your phone and listen to music at the same time.
I have an older car with an old stereo where the only external input is via jack. Worked perfectly fine with my old phone. When I got a new Samsung, I went through the hassle of trying several "combined usb-c charger and audio jack adaptor" only to eventually find out they can only work in on mode or the other, not both at the same time. I ended up throwing away my old phone holder and spending even more money on one with built-in wireless charging so I could both listen to a damn music and charge my phone at the same time while driving.
Just a FYI for anyone that has the same problem. The reason the adapters don't work is that they're operating in Audio Accessory Mode. The signal comes from the phone's DAC, and is passed through the data lines of the USB connector to the 3.5 mm jack. Problem is, the charging mode also uses those lines to communicate. Thus it can't do both.
I have an older car with an old stereo where the only external input is via jack. Worked perfectly fine with my old phone. When I got a new Samsung, I went through the hassle of trying several "combined usb-c charger and audio jack adaptor" only to eventually find out they can only work in on mode or the other, not both at the same time. I ended up throwing away my old phone holder and spending even more money on one with built-in wireless charging so I could both listen to a damn music and charge my phone at the same time while driving.