When I found out that the odo didn't turn over to 300K shortly after an oil change,I started using the trip meter and simply added the miles to 299,999. I change my oil every 3-4K miles. Since keeping track of the added mileage, I have about 335K miles on my baby. I am guessing my margin of error is +/- 200 miles.
Wait till the dash not lighting up so no speedo or odometer, the error factor really kicks in then It starts out with only occurring after short trips, then ramps up to not working unless it has sat all day since it was last turned off, to requiring an over night rest ..... to the stage the taxi Prius reached, the rear door seal dislodging causing the door open light to remain lit in the instrument cluster ...... that seemed to be a great fix, as long as we drove the car every day T1 Terry