A bull bison weighs about 2,000 pounds, whereas a car like this would be twice that. Even though the passengers weren't in much danger (at least not this time), the encounter still gave the people in the car a jolt.
"Foolish tourists in car behind the buffalo [chased] them into our parked car," wrote Tom Carter, who took the video, on YouTube. "Never harass wild animals. Once aroused, give them time and space to calm down. Never chase wild animals!"