We can redirect the air that flows along the sides of the car so that an effect similar to what happens at the front of the car takes place at the rear wheelwells. If the wheelwells are boxed in behind the tires, there will be very little chance of creating a low-pressure area under the rear deck. Most late model cars are very open in this area. Stock-type cars can be modified to open this area within existing rules. Teams must always make sure the passenger compartment is sealed to prevent entry of flammable materials and fire in case of an accident.