How do I tell if loud car sound from outside is from someone running their car in the winter before they drive or if it is from a sub-woofer

Especially if I do not want to ask the driver or go outside to be seen by the driver

I really do not want someone to pay a fine for having a defective car because they can not afford a better one and just be farther away from having the money to purchase a car that does not make sound so that I end up hearing the sound more often

But subwoofering is evil