Speedometer acts all erratic, sometimes will show i am going 30 mph more then i really am, may sometimes show the needle being buried and not going over 20 mph actually, sometimes doesn't register at all, needle is jumpy, and at other times it will go back to normal for a few days without any incidents. this all started happening once my vehicle hit 51k miles. the dealership stated it may be the instrument cluster and could cost upwards of $1300 to replace.