BMW Repair: 2002 BMW Z3 security system problem, bmw z3, factory radio

Question
I have just purchased a new to me 2002 BMW Z3. The problem that I am having with it is that the parking light will just start flashing, as if some one is trying to tamper with the car.  I lock the car with the remote when I get home or get to work and the hazards will just be flashing, and I now no one has touched the car.  I am pulling my hair out over this problem and if you could help it would be great.

Answer
I need a little more info. Does the car lock and unlock properly with the remote? Does the flashing happen while the car has been sitting a while? Does the alarm horn work?, which is an extra horn, not the one that sounds when "hitting the horn". Does everything sometimes work normally? are you parking with the top up or down?
Do you have the factory radio in the car?
       Kimber