DUDU-Meng Then let me try to make myself clear then. I owned an other brand android HU in the past, and that unit came in a fascia, which had that RZC canbus integrated / built in the fascia itself. When I have replaced it and switched to your unit, I had to buy an other fascia, and it came with a separate Daojun canbus box I'm currently using. There was no problem with the RZC thing, I just simply sold it along with my previous unit, so I don't have it anymore. And what I like about the Daojun box? It is simple: It works seamlessly and even better and more reliable than the RZC one.
But if you pay this suprisingly much attention to my issue, in return I would still want to offer my help in any way I could making this canbus box working on my DUDU. Not much I know of this matter, but I learn fast and like challenges! π