2005 545i strange speedometer problem.
So my speedometer has been acting strange lately. When I start the car, sometimes the speedometer needle will have a high frequency oscillation at the "0" reading. It just sits there jumping around at zero. Normally, I turn the key on and off a few times and it stops. Once it stops it behaves normally again. Well today, I could not get it to stop. So I decided to drive away and see what happened (bad idea). It went from oscillating over the zero and shot right up to the 20 MPH indication. Now, when I stop, the speedo hardstops at the 5 MPH setting and won't go below it. Even at a dead stop. It used to sit at zero at a dead stop. In addition to that, the speedometer is now 5 MPH off all the time. I verified this by turning on my cruise control which now reports a speed 5 MPH different from the needle reading. So it looks like my speedo's totally screwed. The car is still under factory warranty so it will be going back to the dealership. I was just curious if anyone here had experienced this problem and what the fix was. I will report back when I get done with the dealer.