the ding that sounds when I shut off the engine varies from dinging only once to three or four seconds worth. I have noticed no patterns as to when it does it several times. Typically it only dings once, but a few times a week it does it more. And no the headlights aren't on. I'm very good about turning them off as part of my post-drive ritual.

 

I'm guessing you are opening the door while the key is near the
ignition.

Try this:

Get in the car, but leave the door open.
Hold the hey fob up near the ignition, but
don't put the key IN the ignition.

Ding, Ding, Ding.

If you remove the key from near the cylinder before
you open the door, I'm betting your dinging will go away.