I haven't connected my phone to the unit. My phone is just connected with Bluetooth to my cars head unit, so calls would just go through there, as they would if I hadn't connected anything with USB.How does it work in terms of connecting to your phone? Does it automatically do it? Does it share the WiFi connection? How do your phone calls connect to your car?
The UX-999 unit has a SIM card slot, and as it's just a normal Android, I've inserted a SIM card and enabled WiFi tethering on the device, so my car can connect to it's WiFi and get an internet connection through it.
Before I had this device, I had a separate USB 4G LTE modem inserted in another USB port in the car to get internet connection in the car.
The UX-999 does support both wireless Android Auto and CarPlay, so you should be able to use that. But I really can't see the point of it, and therefore I haven't tried it out yet. But I've read, that if you use Android Auto this way, it would still use the full widescreen in e.g. the Ioniq 5, but it should kinda stretch the image a bit.