I have a 94 Taurus sedan GL 3.0 V6 with 144,000 miles on it. Over the last year I have noticed that the speedometer needle fluctuates or shakes. It does not happen very often, and when it does it is under 40 mph, city driving. It doesn't move, fluctuate, shudder, whatever you want to call it much and sometimes the shake/vibration is audible. It doesn't cause any problems so I never really paid any mind to it. Just curious what you guys might think it is? Sorry if this is a little vauge. Any help would be greatly appreciated. Thanks in advance!