It might be something more than that. I remember when I was being test driven in a SVX, which I might possibly own soon enough if the I get it to the mechanic and not to mention a couple of other factors. I a car passed to the right in front of us at a light and it was pretty close. As that happened I heard two little honks emanate from the SVX, sort of like how the unlocking honks sound like, I thought my mind was playing tricks on me.
It also happened when a car passed us on the highway.
But now since I heard your account of the honking while in the rainstorm it can mean something else as well. It might mean that the SVX is equipped with some proximity censor that honks at close or incoming objects. And since the rain is technically lots of tiny incoming objects posing as one big mass, especially in a rainstorm and the fog, it throws the censors off into thinking that many cars are coming at you.
Or it could be the wire to the alarm system shorting from being bombarded with rain and I am insane.
