Cars these days are so loaded with electronics, solenoids, valves opening and closing, motors whining, computerized everything, that odd noises are to be expected from them from time to time. Even as far back as 2009, I noticed that my old car's electronic throttle would whine noticeably and click for the first couple minutes after I would shut the car off. It concerned me at first, but then I gave up worrying about it when it went on for months and nothing ever happened. Since most cars are never really completely "off" unless you remove the battery, things will do their occasional self-diagnostics and self tests, things will activate and deactivate when they sense you are in and out of proximity. I could go on. Unless a vehicle makes an alarming noise while it's being driven or while it's running, don't worry about it.