I have a Carlinkit 2.0 and it works great.
The learning curve was that I had to
- plug it into the left USB port in the Essence version, as the other USB ports don't work as they are power only.
- use a really good quality cable if you are using an extension
- disable your head unit Bluetooth setting on your phone, as the Carlinkit uses its own Bluetooth to sign into your phone and then communicates with your phone through the Carlinkit Wifi connection.
- Hence you also need wifi enabled on your phone and connected to the Carlinkit wifi.
- Do not update the firmware to the latest June 2022 version as this version is unstable for the V2.0.
- It will not work if your phone is in Flight mode.
The version 2.0 is rarely seen on eBay these days as it has been superseded by the 3.0.
From what I read on various forums, the 2.0 is more reliable than the 3.0, but many are very satisfied with the 3.0.
The version 4.0 adds android auto and another layer of complexity hence expect more bugs.