car: 94 accord LX 4cyl, auto

noise: faint clunking coming from the driver's side, in the footwell area. only happens when accelerating from a standstill, and sometimes its audible when the car shifts gears.

i thought it was a loose interior panel somewhere down there, but it only happens at very specific times. could it be the axle? the CV joints aren't clicking at all. any ideas?

thanks