Just a reminder what kicked this tread off,
Thursday long trip home in the rain but when I reached dry tarmac really hit the red line to exercise the engine. When I parked up at home the idle was as lumpy as a lumpy thing. Called out BMW assist on Friday morning and mentioned this had happened before and been cured by a reload of idle map in the ECU sure enough this sorted the problem again, it seems my airflow sensors when exercised fully forgot the starting position (idle). Also showed some interest and got a tour through the engineers plug in computer checks everything including heated rear screen performance but noted that it had a hard latch (constant problem) on the airflow sensors plus was showing engine loom out side the test parameters. The BMW "Doctor" wrote a prescription for me to take to local dealer which I duly did and have it booked in for a week of fettling posibly new engine loom and airflow meter. Plus having two kerbed wheels replaced £335 F and £355 R for those who wondered how much they would cost to replace.
Will post when jobs done.