LoyalLexus-er

I have a 14 month old 2003 RX300. For many months now, I get an intermittent loud "whirring/whining" sound in what seems to be my right rear of the car. It only seems to appear when I am going very slowly (under 10mph) and is not related to braking---it comes when I brake or when I am just slowly drifting. It happens when I am turning or just going straight. Naturally, whenever I take it to the dealer, the sound is not there. And of course the dealer tells me that they have never had any similar complaints other than mine. Does ANYONE know what this is about? Is it related to this transmission problem?