Stretching it? How so? It seems like a perfectly accurate description to me. Essentially you put on a new “wheel” and add the battery/control package to a conventional vehicle, and it operates independently. It’s actually a power-split hybrid just like the Prius, in that both electric and gasoline systems provide power in parallel. He calls it a plug-in bybrid because that’s how it is recharged, as opposed to having the gas engine recharge the battery like the Prius does.
“Stretching it? How so?”
Rear wheel drive, drum brakes, available wheel well clearance, a safe and available space for an unknown battery pack - Ironically, an example of one that probably would not work would be the ‘71 Camaro the ABC Wier mentions up front, “even your own ‘71 Camaro”.