I have followed this thread and it's sad to see there has not been a follow up in a year. Is the project dead? That would be quite sad, I consider the GT90 as an icon of the 90ties and I am quite sure it inspired Pagani when he built the Zonda. Simularities are f.e. the glass bubble cockpit, the sumptous interior (dash with central carbon pedestal, milled alu switches, styled floor matting etc.), the visible and styled intake manifolds and ofcourse the way the exhausts are designed and positioned.
I am always on the lookout for new pics and info about the GT90 because I am making a more accurate diecast model of it. Unfortunately not many details are known because it's only one car and not road legal. So it's quite rare to find new footage. It hasn't been out often.
There does not seem to be a thread that can be filled with links to GT90 info, therefore I am posting a link I recently found. These were probably made while the car was readied for auction. I recently was given the opportunity to see this one of a kind car up close. 1995 Ford GT90 Concept - Album on Imgur