Hi guys. I've had my 2004 G35 sedan for a little over a year now. Lately, I've noticed some creaking or grinding noise from the rear left suspension area, and sometimes on the right too, when I go over severe bumps or sometimes when I'm making a semi-fast turn. I also tried bouncing up and down in my driver seat and the sound was quite loud. Does anyone know what could be causing this? This doesn't happen all the time, and the noise is usually more pronounced on cooler days...

Thanks!