Fastest land mammal in the world is a cheetah, they top out at approx. 60 mph. 2nd fastest is a race trained greyhound, they can accelerate up to about 45 mph in 2-3 strides, bears can move faster than an human can run but they can't run faster than someone driving a car, particularly a car with it's doors locked and windows rolled up. Presumably you drove the vehicle to wherever you're sitting, presumably you can also drive it away, why in the world would a person willingly engage a bear or any other critter for that matter, when they can drive away?

Not trying to be difficult, I just don't see a problem.

Not to mention that using a road flare as the means for defense means that you're going to be within arm's reach of your opponent. Why get so close when you have a steel encased movable box to use?

John E