Annoying Beeping Noise!

Just wondering if anyone can help me locate where this beeping sound is coming from exactly on my 1996 GT vert. It happens everytime I start the car up....its either 5 sets of 5 beeps, or 6 sets of 6 beeps....can't remember which. Its coming from somewhere under the dash, I belive under the passenger side. I know its not the seatbelt warning because I can hear that one and it turns off when the belts are buckled. This beeping I'm talking about won't turn off until its done its 5 or 6 sets. I also noticed that when driving for about 45 minutes to an hour, it will start up randomly, while driving. It then keeps beeping until its 5 or 6 sets is up. This happens on every start up and is pretty loud and annoying. Anyone have an idea of what it could be? Thanks in advance.

not that I'm aware of. All I have is the stock remote entry....something funny with the car tho....if the car is locked up and I use the key to unlock the door, i'll open the door and the car lights will start flashing on and off, but there is no alarm noise like a horn or siren. When this happens the ignition is cut and you can't start the car until you unlock the car with the remote. Is this the stock car alarm? I have the theft flashing light on the dash which is stock....all I really care about right now is getting rid of that annoying beeping.