You said that you can hear it at low speed, so try with someone driving reproduce the conditions you hear the sound. You stand by the car and follow it on foot and try to hear it more clearly. Try with the hood open. Check for bad upper mount strut bearing, also called topplate bearing.

Nic.

Contour 99 MTX V6 fully loaded, stock with 110000km. Illuminated sunroof switch. About to do the mystique rear dome light conversion with eyeball dome light.