NYC530XI

I was wondering if anyone has any experience with this issue. My car when the brake is engaged in drive, and also in park, has a bouncy/fluctuating idle. It jumps from 600rpm to 800rpm typically, and sometimes it goes as low as 500 and closer to 1000.. The problem is more pronounced with the seat heater, steering wheel heater, climate control etc, but it does happen even when none of the above is engaged.

From internet research, I have found others who have had similar issues had fixes ranging from Idle Control Valves, to Mass Air sensors, and even in some cases entire VANOS system replacements.

I bought this up to the dealer, and since it doesn't throw any codes they said nothing they can do. I am bringing it back next Friday and I would really like this addressed. Even though it doesn't affect drivability, it is quite annoying, and now amplified by the new RPI exhaust.. (the exhaust note is as erratic as the idle... ) Any 3 and 1/2 year old car should be able to hold a consistent idle..

Does anyone have a SIB or another angle/perspective I can approach my SA with this issue? Any thoughts are appreciated.