When Michael and Maria are pulled over by the police on the highway, Maria's belt goes from buckled to unbuckled to buckled when the angles change.
Kyle follows Liz, Max, and Isabel to the motel in Texas, even though he had no way of knowing where they were.
However, Kyle found all of them the same way Liz, Isabel & Max found Michael & Maria: he knew what highway they were on and he saw Maria's disabled car on the side of the road about 100 yards from the motel.
At the 16:45 mark Maria's seat belt is off. But then at the 16:48 mark it's back on.