From the Peoples Republic of Boulder comes the following:
The city of Boulder asked for $6 million to "...[p]rovide funding to convert 60 hybrid electric vehicles to Plug-in Hybrid Vehicles with Vehicle to Grid technology. The cars are part of the City of Boulder, Boulder County, and the University of Colorado fleets." The retrofit of each vehicle, therefore, would cost $100-thousand dollars a piece.
In case you missed it, that is one hundred thousand dollars per car.