Now I have measured the stand by current. After a couple of minutes it goes down to 90 to 100 mAmp, earlier it was 120 mAmp after that time. Much better but far away from your stand by current. I think the stand by current was much higher during the winter, even at +5 degree Celsius I got trouble to start the engine after 3-4 days. New battery, new alternator.

Maybe I shall replace the radio this winter. A 4x4+ Watt radio will do it. Maybe problem to connect it to the rear speakers without a filter, the rear are subwoofers. Better sound and maybe I reduce the stand by current with some more mAmps.

Here is more detail, at bottom, of the measurement of the currents.

Thanks for the help !

/Lars