Its not that beep from the chime it is coming from the engine area and a very low beep, I hear it when I go to the garage randomly to get something.
It sounds exactly the same. I had a video but upgraded my phone and lost it.I have it also on my 18. You are not imagining things. It is more of an intermittent whine than a beep. It is definitely coming from the engine compartment. I first noticed mine 1 1/2 hours after the vehicle was off while in the garage. I have a video of it because I figured the dealer would think I was crazy. At first I thought it was the ABS control module mounted on the passenger side firewall. The dealer kept the car for 2 days and of course couldn't replicate it. Another time I noticed it (in driveway), I was able to rule out the ABS. Dealer said whatever is doing it will be vibrating and should be able to feel it if touched (obviously do when engine is cooled). One trick a mechanic told me is to use a screw driver to touch the area and you should feel it that way. I don't have one long enough as it appears the sound is coming from deep in the compartment.
I'm going to try to post the video and see if its the same thing you are dealing with.
So today while changing the rear brakes on the car I heard a beeping on and off for 3 seconds every 30 seconds. Initially I thought it was some outside noise as I've never heard this noise before but upon closer inspection it seemed to be coming from the engine bay. I popped the hood and began to listen around and it seemed to be coming from the area of the engine on the passenger side. Of course when I went inside to get my cellphone to record it, it stopped and didnt do it again.
This is the first time it's done this. The only thing that's different today then any other day is that I was moving the back rotor around back and forth while I was trying to take it off since it was seized on.
Anyone figure out what's going on with the beeping?