When I am driving I hear a little noise. I cant tell where it is coming from and it really has no pattern. It happens about every 30-60 seconds when I am driving. Its very quiet and its a little pssshh sound, almost sounds like air is coming out of my tires and it stutters for a brief second. It is not very noticable but I notice it. Just wondering if anybody know what it could be. I think it is coming from the rear and it just kinda stutters for like half a second and makes a little sound like air is coming out of my tire or something but I dont think that it what it is.