So my moms car when driving starts making a.

Hi so my moms car when driving starts making a very loud buzzing, rattling sound that seems to be coming from under the drivers seat and at the left side of the back of the car. The sound is extremely loud, I'm not to sure if buzzing or rattling can completely explain it all I know is even with the music on loud its still barely drains it out. The more speed you go the faster it goes. I am just wondering if it could potentionally be the breaks at the back as this would be a major concern. Thank you