Steve

How long do you expect to play a CD for, when stationary and not running the
engine?
I played one for 15 minutes today, in my new Sony CDXMP40, which has just
been fitted in my new (used) car which I bought last week (so I'm not
familiar with either, or the previous condition of the car battery), and I
ended up with a flat battery. Had to call a mate out with his jump leads.
I have standard-ish door and parcel-shelf speakers.