I have a mobile home and have got a bit of an idea, as the current stereo is very small and old. So I found it here Link to the din stero
SO I got a little idea to mount an RPI with HA, to check different parts in the motorhome, eg fridge/freezer temperature. solar cells, and so on.
But can I have a kiosk in this? or are the other alternatives?
Take a look here in the forum, search for “RV”. There are a few threads about this, not many, but it could be a start.
But I doubt, that you can connect the linked radio to HA. But in the end, it shouldn’t be necessary - just use a touch screen display together with the Pi. They are not that expensive, and work good, considering the unusual circumstances.
There are a few videos on youtube, like this one, or you checkout this guys channel, he has some very extensive videos about his CarPi: 
Thanks for the links. Will have a look at it.
It may be easier to install a 5G network and run the HA app, it should work well since the screen has an Android 12 OS in it.