In a car, the amount of gas remains constant, but when driving down the road the temperature of the tire and gas increases and so does the volume of the tire. Tire companies take all of these into account when creating a tire
While scuba diving theories sure become more and more as you go deeper. If the diver ascends with full lungs on a warm day, both the temperature and pressure decrease and the volume of the air will increase rapidly. The diver has to exhale as he ascends to prevent lung damage.
Combined gas law is most commonly used or seen in machines with a gas or some type of fuel
Only law, besides ideal gas law, that combines all three variables