Drivetrain Transmission Problems... Please Help.

when I had an automatic transmission in my Stang, I had a similar problem. I'd be driving along and the transmission would suddenly shift into neutral, then after a second or so it would shift back into gear. This would repeat a few times then would go away for a while. The issue turned out to be the gear on the Vehicle Speed Sensor (VSS). The plastic gear had stripped and would slip now & then. The computer uses the VSS to determine your speed and then select the correct gear. The stripped gear confused the computer and caused it to shift strangely. I would check the VSS gear and the wiring going to it. If I remember right, the VSS is a blue sensor plugged into the transmission on the driver's side at the back, near the driveshaft. One bolt holds it in. Also make sure the wiring leading to the VSS isn't damaged.