Hi and welcome! For that mileage I would change fuel filter first and pour bottle of injector cleaner into gas tank during next fill up for the beginning.
Also fresh battery may help. Overnight it gets discharged causing rough idle after start, and next thing you may not start the car some day. I had this, you may search "car not start". What you have is may be early symthom or dying battery. You may find perfect aftermarket for half price vs. original BMW. Works just fine.
Last edited by LX-biker; 10-13-2012 at 11:20 AM.