if you care, you might talk to building management about this. I also live in a building with a garage and there is a very strict "no idling" rule. it's bad to

if you care, you might talk to building management about this. I also live in a building with a garage and there is a very strict "no idling" rule. it's bad to have unnecessary CO emissions in a somewhat enclosed area in the first place, but it can also set off the detector and then everyone has to evacuate the building.