Seriously right now?

Ok so this summer the people 2 houses away were annoying cuz their car stereo was loud and my window was open. Today I was trying to go back to sleep around 8:45 am (up part of the night with sick baby and then up at 6:45 for online work) and I could hear a stereo almost loud enough to hear the words. It was the neighbors 2 houses away and their car doors were shut and my window was shut! It was going on for over 15 minutes. Why do you need to warm your car up for 15 minutes? No one was in the car, which makes sense cuz otherwise they would go deaf! Moga thinks they must have it cranked up cuz if they are leaving it running for extended periods of time they want to know the second someone steals it...