https://www.amazon.co.uk/STM32F103-Arm- ... 1970054018
This I could get used to. So been working on this in my "spare time" and finally bit the bullet and designed a board and of course ordered 10 from JLCPCB because Damien designs always work first time

Features :
-12v power
-Fits behind 4.3" nextion display and fits a dash phone holder.
-Molex mini fit jr connections (ripped off from Tom)
-2 CAN channels. One based on the onboard STM32 controller , the other using a SPI MCP25625
-I 12v digital input
-1 low side switch output
-Measures 12v supply via adc
-USB on Serial 1
-Nextion on Serial 2
Uses :
-General purpose interface and display for all VCUs (leaf,gs450h etc) over can. As the Nextion is a touch display it allows for sending data to a vcu as well as receive. e.g. changing power settings.
-Display for Openinverter BMS. This is a major design goal as it will be going in the E65 very soon.
-Display for any CAN based bms e.g. volt and bmw.
-Controller for openinverter boards via can. Going in the E31 for this purpose.
So there it is. Will be opensource on github once I get the bugs out.