My car has done this since the day I bought it and I can't figure out why it does it. The car idles slightly under 1000 rpm, maybe 900 or so. When i am driving and I am coming to a stop, or rolling slowly through a parking lot, the car will idle around 1100 or 1200 rpm until I come to a complete stop. I can have the car in gear or out of gear, hot or cold, and the thing still does it. It is an M6. Also, when it comes to a stop, sometimes I have to burp the throttle to get it to idle down to the normal rpm. It's like it has nothing to do with the motor, more like if the wheels are rolling or not. Any help would be greatly appreciated.

 

Anyone???