All of them do it? Hell, I'd be willing to buy a whole new kit to make this stop. It's really loud. I love the light output but I don't think I can keep em in while they're buzzing so loudly. When I'm driving 35mph with the window down and no music playing, it sounds like my car's being chased by a bunch of hornets.
I had this exact kit in my 96 Mark VIII and it never made a sound.