Megan reads a Fortean Times magazine article on the summer solstice, which states "For scientists, this simply means that the sun will be at its closest point to the Earth..." This is not the definition of the summer solstice, and is not true. Perihelion is the point in Earth's orbit at which it is closest to the sun, and occurs in January. The sun is actually farthest from the Earth in July. Scientists would know this.
During all the interior scenes inside of the Ford Expedition, the transmission selector on the steering column is always very clearly in the park position. This clearly reveals the vehicle is being towed or otherwise not operating under its own power.