well, DUURRRR..... lessee here, you've got a motor spewing out hot gasses, of COURSE that can be used to generate power. That's what a turbocharger does, that's what BMW's steam turbine tech does, there are a million and a half ways to use a temperature difference to generate power. Just like it's a big no-brainer to recapture the mechanical energy of a car through regenerative braking.
The problem is that nobody is willing to pay for this kind of tech to be integrated into their vehicles, so we still end up with 99.9% of the population puttering around in conventional gasoline vehicles and the few who do opt to support technological advances like this are labeled as eco-nuts for buying a hybrid.
I guess I'm just getting a little bored of seeing all these "miracle devices" getting thrown around in the news without any regard to the actual impact they will have. Especially when the tech is old news, and the only newsworthy aspect is that gas prices remain high.