For the past few months I have been hearing this kind of buzzing/grinding noise from what sounds like the front passenger side of the car. It seems to happen more when I press lightly on the brakes but I have also heard it when I am just coasting and am not pressing on the gas or brakes. I do not hear it everyday so it didnt worry me at first. But now its been awhile and the noise still comes and goes. Also it only happens in the city, when I take it on the highway the ride is flawless. Any ideas on what it could be? I have also been looking for the transmission cap under the hood and cant seem to find it. Anyone know where it is?