Lexus GS 2013+ :: 4GS F Sport Whine That Goes Up And Down With RPMs

I have a 4GS F Sport, about 2 months old. For the past few weeks, I've been hearing a whine that goes up and down with the RPMs. It almost sounds like the noise you would hear if you didn't ground an aftermarket radio correctly. Not sure if it was there when I drove it/bought it - I think I would have noticed it, but it seems to be getting louder, about as loud as the sound of the engine (unless I'm really getting on it and the resonator kicks in).

I have a buddy with the exact same car (different color, bought it a couple of weeks after I did) and the whine on his sounds much quieter - still there, just quieter. I've spoken to the dealer twice and have ridden with a tech. We drove mine and a GS Luxury. In the Luxury Edition you hear it but it is quieter, which he says is added insulation (first time I'd heard of any difference like that between the two). The tech said it is likely the alternator which is triple wound to handle all of the electrical requirements and it's just the way the car is.