So ya this was the first time i have driven my car the 700 mile trip to AZ. and it did fine. but the day before I left to come back to UT I noticed my car was not shifting into overdrive at all. so I stoped and I checked the Transmission Fluid and it was about 2 bottles low lol. so i filled it and it stoped. (for a while) the whole trip home the only way I would have overdrive is if I turned the car off and back on, and then it would only stay on until I had to pass and it would shift into 3rd to pass and would just stay in third. any ideas on what it could be. is my transmission shot? my car just barly turned over 103,000 miles. so ya any ideas???