I'm just using an Arduino Nano &
CAN BUS module:
The HIM doesn't support 49.5c but that's the max. cabin temp that can be displayed - 77c outside (though the FG[I] went all the way up to 99c).
The Arduino
CAN BUS software libraries came with some examples and I was dumping data out of the car in no time.
I've got quite a few modules from the FGX too, the instrument cluster (I didn't realise the extra box on top was the GPS component), the
BEM/
BCM, fuse box and entire front loom. There's another module there with a 2nd OBDII port, says it's the Smart Data Link Connector.
I tend to agree with you though (why wouldn't I, you've done this!) that it's going to be a case of swapping over more parts rather than less (my screen only idea). The front buttons not going into the FDIM and the extra cluster module tipped me over that line.