Abstract: A system for use in a vehicle, the system comprising sensors located on the front and back fascia of the vehicle; processors coupled to the sensors; and a memory including instructions, which when executed by the processors, cause the processors to perform a method. The method comprising detecting a change in first acoustic impedance at a first sensor while detecting a change in second acoustic impedance at a second sensor. In accordance with a determination that the change in first acoustic impedance and the second acoustic impedance are between a threshold range for at least a threshold period of time, the method executing a precautionary measure. In accordance with a determination that the change in first acoustic impedance and the change in second acoustic impedance are not between the threshold range for at least the threshold period of time, the method forgoing executing the precautionary measure.