Very interesting instructions! thanks for sharing. May be there is a way to make it easier? For example, something like this one https://www.eltima.com/products/usb-to-serial-converter/
did you mean this solution http://www.eltima.com/products/serial-over-ethernet/? or any other?
If you need remote access to OBDII to make the diagnostics with the help of mechanic you can use this software http://www.flexihub.com/remote-vehicle-diagnostics/