When the cabin is quiet (radio off or low) I DO hear the click of the relay when I switch on the heated seats, wheel etc.
I figure the reason I hear it in this vehicle is because the battery is under the Passenger seat, and so the relays are there (or under the drivers seat).
Anyway, no matter.
The reason I don't hear them in my other vehicle is because the battery is under the hood, as are ALL the other relays - THERFORE no clicking.
I don't let stuff like that bother me. Wheels falling off, or motors blowing up bother me.