I honestly thought of doing something simular. I have access to a generator that I can get in to a small room with a bit of effort. The idea was to try and get the room as air tight as possible and then just sit there while the generator is running.
Getting it inside an SUV though? Depends on how big it is. I would also worry about the heat coming out of the exaust.
You could in theory do the hosepipe leading in to the SUV while the generator is outside of the car.
It's risky in the sense that people might wonder why a generator is running...
You will have to make your own judgement on this though. Im not sure how long it would take and how dangerous it might be if not successful. I assume brain damage could be a result...