having this weird issue when driving on the highway at speeds generally above 55. I'll be driving along fine and then all of a sudden my whole dash goes kaput! the speedometer passes 120 and on, the odometer doesnt show up (although the milage is correct when it comes back on), the tach goes to 0, just nothing. after awhile it seems to correct it self and come back working. But it has happened for awhile a couple times, the car seems to fine though. any ideas? thanks