This would never happen in the UK or Norway as petrol costs too much and people just would not have a house big enough that they would not notice an automobile

This would never happen in the UK or Norway as petrol costs too much and people just would not have a house big enough that they would not notice an automobile engine chugging away right next to them. Cheap petrol in the USA means that people are in the habit of doing things like starting their car remotely to 'warm up' or 'cool down' before they then have a shower, brekkie and what not before finally getting in their car. Usually the car is on the driveway and not the garage in these scenarios, however, that is something that would not happen in the rest of the world, where petrol costs real money in part because a U.S. dollar has to be bought in order to buy the oil that is always priced in petro-dollars. Given that people do suicide themselves by connecting some hosepipe from the exhaust to the interior of a car I am actually surprised that there are not rules regarding CO detectors already. CO can not just kill the occupants, you could have a big pile-up on a motorway due to CO poisoning. This happened a few times with police cars last year and 3/4 of all CO deaths are due to vehicles, not central heating or other sources.