Maybe some people here have been following this more closely, but it's news to me. Some guys swapped a 1.2 liter VW TDI engine into an insight, and claim to be getting 90+ MPG, expecting to break 100.
The site has been slashdotted, but the google cache'd version seems to be fully functional: link
If you want to follow an on-site link, just type cache:<url> in a google search.
Diesel electric hybrid in short, genius, but as I understand Toyota has made a European Prius Diesel and a Sport Prius with a turbo gas engine and the hybrid system. Course in Europe people rarely own an SUV or a pick-up, so Toyota has a secured sedan market there, here Toyota has to compete in all the compact, sub compact, sedan, sport coupe, truck, and SUV market, so we just get the basic Prius.