I think the issue is the ECU is not shutting down. The light stays on regardless of the doors being locked or unlocked.
Factory told me this was because Charles likes the lights on because it looks cool.
If they do power off after 5 minutes then fair enough I guess.
As Simon says there are a whole bunch of things that drain the battery, and it's a common issue on other cars.
Having said that my 10 year old BMW on it's original battery constantly says it is flat, but never ever actually does run out of juice. It never gets charged, and I regularly sit in it with the ignition off waiting to collect liz from the station with the stereo on and the heated seats blasting, plus it has alarms and various led's that never go off. C'est la vie I suppose..
