Watch this... I was expecting some pie-in-sky Greenie startup intended to suck up govmint money.
No... it's cheap, simple to install, add-on power.
Boston Start-up Converts Commercial Vehicles into Hybrids | MIT Technology Review

{Yes, I GET it doesnt work without the stock engine. And that it only works on RWD, for now - only would need new TC design to fit further back for 4WD}

ADDED: So you guys get your thinking cap on and name what other component it needs to make it a more complete 'hybrid'.. not just a 'wall-charger', but related.