Plug-in Hybrids Get Astounding Mileage

Suppose you could take that high-mileage Prius sitting in your garage and modify it so that it gets 180 m.p.g. rather than 45? This is the question that a couple of inveterate tinkerers asked as they set out to make their fuel-efficient car even more fuel efficient by plugging it into the garage wall outlet at night. Not surprisingly, Toyota and Honda frown about this kind of modification to their carefully engineered creations. Will such a vehicle be available commercially any time soon? [New York Times, requires registration]