The tranny won't shift properly when the speedometer wasn't working. GPS speed is no benefit. Repair was only real option although the car was still drivable it didn't know when to shift.

My speedometer has always run about 2 or 3 mph fast but then it started to run about 12 or 13 mph fast whenever I drove about 70 or 75 and up. Now it will either do that or remain at 0, tending to do the latter. This is not a huge deal for me because I rely so heavily on my gps which also tells me my speed but it can be annoying at times and would be significant to those are good navigators and concerned about being law abiding citizens.

speedometer bounces up to 60 then back down when idling

I don't want to go off . . this is my 3rd toyota corolla wagon, and the only one that has ever had this problem . . my mechanic looked at me as though I had 2 heads when I reported this to him . .I wish that Toyota would start making this station wagon again . . this is the best little car that I have ever owned . .