Yep, the ST sure has the spot, so the instrument cluster is probably sourced from the same place or at least made to the exact same specification as the STX's.
What's to be determined now is how much of the wiring is actually in the ST. As we know, the STX had everything except the bloody sensor itself - you sorta wonder why they stopped just short of the magic moment sorta thing.
In the ST, is there any wiring heading into the engine bay at all, or is it missing all the way?
According to my D40 manual (in DI.pdf, page 6 of 70), pin 49 of the "combination meter" (instrument cluster) is the outbound signal and pin 50 is the inbound signal.
Worst case - assuming the instrument clusters are identical - you could run a pair of wires out from pins 49 and 50, through the firewall into the engine bay and cable-tie them to the framework in front of the intercooler/radiator assembly, where you can stick your thermistor.
I actually found it curious that it refuses to display below -30C or above 60C. There are places on this planet that experience both - is Nissan trying to tell us not to go there?
