It would be better if you gave a reason why you should be worried. That casing is about as fireproof as it gets and those model-s incidents where there was a fire the occupants made it out without so much as a singed hair on their legs.

I'm sure given the 'right' conditions you could get a catastrophic release of energy out of a pack this size but I'm fairly certain that the occupants of the car would not be in a state where they would realize that the battery had also exploded since they'd be too distracted by evaporating themselves.