Volkswagen recently built twenty prototype diesel plug-in hybrid Golf prototypes for a field test of the technology. AutoExpress magazine in the UK recently had an opportunity to try out the so-called Twin-Drive Golf. The Twin-Drive combines a 1.5L diesel with electric drive and lithium ion batteries with plug-in capability. A pair of wheel motors turn the back wheels providing all wheel drive capability while a third motor and generator are combined with the diesel engine at the front axle. With a very light foot on the go pedal, the Twin-Drive can go to 31 mph on electricity alone. It can reportedly go 30 miles on a charge of its Sanyo battery pack. The plug-in hybrid hardware adds 550 lb of mass to the Golf but it yields up to 94.1 mpg (U.S.), according to VW. AutoExpress says the even distribution of the new mass keeps things balanced but the car does feel heavier than a standard Golf. It's unlikely we'll see a production VW with this configuration anytime soon though. The cost would simply be prohibitive.