I am new to the Board so am not sure if you have addressed this in the past. On my 2000 M Coupe the throttle does not always return to idle when the clutch is depressed. The idle control valve was replaced, but this still happens - but only every once in a while. I can come to a stop sign and be idling at 3000, rev it up and then it will come down to normal. Nothing obvious like floor mats sliding up...