Like Tom, I was only aware of this being a Quincy Lynn product, self-built from plans, and didn't know of the Triumph Spitfire base, so the plot thickens...
Is it an American kitcar?
Centurion perhaps?
I believe they called it the Urba Centurion,diesel-powered sport-coupe car,it used a Kubota diesel engine.I understand it was by CrazyJerry-1982?
Was it Robert Q. Riley and David Lynn Carey,and was on a Triumph spitfire chassis?