Could be a single electric motor driving the 2 wheels through a differential. This site has pictures of 2 motors that would fit in in the transmission tunnel,

Could be a single electric motor driving the 2 wheels through a differential. This site has pictures of 2 motors that would fit in in the transmission tunnel, leading me to believe they would attach to a traditional drive shaft. http://www.nedra.com/build.html http://www.nedra.com/build.html Cursory search didn't bring up any undercarriage images to prove my theory. This is a concept, I'm not sure the engineering for 4 motors to work in unison is as easy as using some conventional drivetrain stuff and just swapping the power plant 1:1.