Carplay UI Modification?

[arpan3t]

I see discussions around modifying the UI of the Carlinkit (initial setup screen, web UI, etc...) but I'm curious about modifying the actual Carplay UI. For example:

• Removing the square button borders around the controls (assuming these are for non-touchscreen head units).
• Removing the rounded corners of the display's edges (typically reserved for displays that have a bezel around them and therefor not using the full display).

My wired Carplay doesn't have these UI elements so it must be the dongle displaying them. Has anyone found the code responsible for displaying the Carplay UI and successfully modified it?