Warranty Voiding for Fun and Profit: 76.1 MPG in a Plug-in Prius

One of our geezeeky friends sent us this Flickr-posted mileage documentation from a Toyota Prius converted to plug-in operation. Looks like someone's kids won't be getting their Mobil Upromise points this month.

The plug-in hybrid electric conversion was done by Energy CS for PG&E. The finger is pointing out that on the last trip (about 40 miles) the vehicle was getting an average 76.1 MPG!

Earlier this year, the UK's AutoExpress reported Toyota was targeting 94 mpg for the next-gen Prius, due in 2008. Is a factory plug-in imminent?

Related:
How to Void Your Toyota Warranty, 101: Hacking the Prius [internal]