I have a puzzler for ya'all. My wife parks her Forester in the garage and at random times I walk by it and hear a buzzing/humming from under the car between the rear wheels. I am pretty sure it has to be the fuel pump running. But why? It'll just start doing it at any old random time for several minutes at a time. No key in car. Car cold. Car hot. I never hear the WRX doing this, just the Forester. 2015. 0 problems or other issues. Any ideas why it does this? Thanks.