2005 645ci Idle
 

Hi Guy's ,I have a 05 645 ci which has an none steady idle it seems to move 20rpm not a great deal even when in cruise.Now my garage says this is normal and not to worry .OK not worrying but annoying any idea's Fuel(run 95 octain in the UK) Plugs/coil/ maf sender? also on downshift to stop the rpm seen to rise a little which looks like you are doing racing change not a lot but still its not on my X5 again they say its normal?
Thanks