Just curious, but can anyone tell me why my car does the following? 1) Idles very loudly at start up only to settle down after a couple minutes (not running at higher revs). Keep in mind that I have the BMW performance exhaust - whatever that means. I love it. I just don't understand what is physically taking place that would cause such a difference. By the way, my wife insists that the neighbors must all hate me for having such a loud exhaust at six in the morning. I reply with, "Just the mothers of small children. The guys love it. I promise." 2) When I first open the door in the morning, there is an electrical humming that occurs. It reminds me of my 1983 Toyota Celica back in the day that would hum while the antenna raised to its full upright position. None of that here.