I have an 04, I go out and sit in my car over breaks and within the 10-15 mins of sitting with the car running the bas/esp and abs lights come on the spoiler goes up and my stereo loses power all at the same time. I replaced the battery a week ago and it took care of the issue. Is it possible that the alternator is bad? Or could it be a sensor or relay of some sort? I haven't gone out to test voltage on the battery yet but i will be later today and will keep updating any other info I may find that could help resolve this issue. Thanks.

 

My guess and it's just a guess, would be a failing alternator.