04 pontiac grand prix gt

Power drain,s/shorts are hard to pinpoint even by a good mechanic he nay find it but will be time consuming and costly,you can do this your self if you have a volt meter,hook volt meter to charged battery/12 volts,then pull one fuse at a time from your fuse panel and wacth the meter for change/raise on meter,when you hit the right one you will see it go up.

And of course check the obvious. It's easy for an interior light to be switched on and go unnoticed, especially if you park in a well lighted area that doesn't really get dark at night.