While driving along today, the speedometer on my Midget just completely stopped working. For the past few days I'd been hearing a new "whirring" noise under the dash or from the left front of the car. I'm new to MG's, so I don't know whether my cable has broken or whether it's a problem with the speedometer itself. Since it quit all at once, it feels more like a cable problem. Does anyone have experience with this?