I believe the Qs - which is found many place is for when the top is open.
My selection of answers that make some sense, although I haven't gotten mine to stop, except for a little while yet!
Make sure the arm that you pull and twist to unlock is totally fully clicked back in it's holder before opening. There is definately a sensor that says this is in the strong position .
In the bow next to that mechanisim (near a securing spot) there is a sensor that goes bad. (One of the more common reasonable sounding answers (found above too) - especially as the car ages - it seems 5+ years and one can imagine where it is gets a bit rusted).
Same idea as above - and because of what it is - the sensor is just dirty and confused. Try cleaning with something that does not leave a residue.
Again the idea above, but with better - where and how. (This just sounds like the million $ answer for most): There is a small switch where, when closing and securing the top, it triggers the flaps to close. Location: passenger side windshield frame. What to do (might move the seat back and stand up). Place your pinky finger pointing in toward the driver's side and you will feel a little metal switch. You should be able to lift this up and down with your finger. Get some electrical grease and coat the switch as best you can. The problem is that a great deal of road grime accumulates and covers the switch.
Assorted suggestions to disconnect the buzzer or electrical: All bad. These cars like most modern ones have computer checks that do NOT take well to any override.
Clean all the seat buckle connectors. The top has sensors for these too. Maybe has greese on it?
The dual key turn in the drivers door to unlock fixes alarm problems like this in many cars.