[Sluttypatton]

A nitrous tank can also rupture, and the impact of such a rupture would certaintly go "kaboom" and kill or maim you. Plus the inhalation of such a massive quantity of nitrous (assuming your still alive after the kaboom) would certainly kill you. Upside: the nitrous probably won't feed the flames, unless the flames get pretty hot and unbind the nitrogen and oxygen...but if your car is in flames, you still got problems, nitrous or no nitrous.

You are right though, oxygen would certainly cause your car to burn very quickly and violently.

Nitrous bottles have (rarely) been known to explode in parked and unmoving cars. They could also rupture in an accident.

It boils down to bottle placement, and safety...don't mount the bottle in the cabin please; it's dangerous and illegal, mount it in the trunk.