Most of the stuff MythBusters did was just fun science, but THIS time it has a serious, real-world impact.
One of the MythBusters experiments was focused around automobiles and the idea that you can't open the vehicle door once it's submerged. They tested that theory and discovered a number of facts about the process. One major takeaway was that, while the door can be difficult to open while the car is sinking, it opens easily once the car's interior and exterior pressure has become equal.
Theresa Booth, a woman living in Minnesota, watched that episode. Then, one day shortly before Easter, she and her daughter were in a car accident that sent them plunging into the water while still inside their vehicle.
Theresa believes she's okay today thanks to what she learned from that MythBusters episode.