Cheap shot on my part.
"I'm just not sure it's worth doing."
The conventional wisdom would say, "No, we've tried that, and it didn't work."
I'm suggesting we look at all the systems together, and find a way to recover the energy of the heat that is thrown away in the radiator.
At the very least, a system which allowed some heat storage during close-haul trips could be coupled to housing units, to distribute "free heat" into the house after you run down to the store for milk, bread, and eggs.
The current "energy crisis" is not the shortage of the seventies. This one is for the long haul, and we have to put our thinking caps on. It would be stupid not to.