This just started , it randomly goes off with the horn honking. I'm still able to start the car but now I noticed that my lock button on my clicker for the car doesn't work. It doesn't work on my backup one either so something whacky is going on. Is there an easy way to disable the stock security system?

 

IDK.

My 2008 TL's alarm went off when I inserted the key into the ignition early this past spring. The ignition turned on, but I still pressed unlock to stop tge honking. Never did it again, but I hear 3G's do have goofy alarms sometimes!

 

Check all of your door lock actuators, trunk lock mechanism and hood lock, one of them may be malfunctioning causing your door not to lock

 

I ran into a similar issue years back.
It was due to a leaky windshield. Started not to long after having it replaced. Seems the shop used a sub-standard glue which eventually separated and allowed water to enter and leak onto the MICU.

Dash would acknowledge that some doors are ajar but they werent.
Wipers would go on spontaneously
Alarm would just go off in the middle of the night.

One weird solution I discovered was leaving the drivers seat belt latched on even after exiting the car. That stopped the alarm from going off at night until I had the windshield re-glued.

Check your sunroof drains and possibly any water that would be entering from the windshield.