I first got my Car Thing in early May. When I was first setting it up, I followed all of the directions correctly and I ran into an issue. The Car Thing said continue in the Spotify app or something similar to that. I already had the app open and my phone bluetooth was paired to the Car Thing bluetooth. After just leaving the app open and Car Thing turned on for 2-3 minutes it finally showed the home screen and stuff on the screen and started working.
I asked 2 other Car Thing users (one of them being @Billy-J) and one of them being a commenter on my video here, and they had a similar poor setup experience. The video commenter said they tried 2-3 times waiting several minutes, and it finally worked after reinstalling the Spotify app on their phone and a Car Thing factory reset by clicking the settings button on Car Thing and scrolling down to restart and then choosing factory reset.
It works pretty great for me now, but the user is left wondering why it's taking so long or if their Car Thing is defective when they first set it up. My thinking is that it is updating the firmware for the first time and that is why it takes so long for something to actually show up and happen. I was setting it up at home in the car in the driveway and connected to strong WiFi so I have no idea what's going on. I'm reporting this so other users can reply and say if they are having the same issue. I also wasn't able to reproduce this issue by factory reseting Car Thing and trying the setup process again. The setup process worked smooth after a factory reset. So my thinking is that it's updating on first boot because I saw some old UI elements at first and then it updated and looked slightly different.
So if you are currently frustrated when setting it up for the first time my advice is to just be patient and keep trying. Make sure WiFi or cellular connection is good and that you followed all of the directions and just give it some time to do it's thing and it should start working.