XDA forums has a very active subforum on Joyings. (https://forum.xda-developers.com/android-auto/android-head-units)
See my thread "Joying Extra Tools apk - an apk to help you install mods, tweak your unit, etc.". (https://forum.xda-developers.com/android-auto/android-head-units/joying-extra-tools-apk-apk-to-help-t3628200)
See (most) radio app example skins. (https://hvdwolf.github.io/Joying-RootAssistant/RadioMods-examples.html)
(That is also where the displayed image is coming from)
See my thread "Joying Extra Tools apk - an apk to help you install mods, tweak your unit, etc.". (https://forum.xda-developers.com/android-auto/android-head-units/joying-extra-tools-apk-apk-to-help-t3628200)
See (most) radio app example skins. (https://hvdwolf.github.io/Joying-RootAssistant/RadioMods-examples.html)
(That is also where the displayed image is coming from)