Where do people draw the line (metaphorically speaking) when it comes to mapping car parks. A shop down the road from me has a single parking space around the back for customers’ use. It would not occur to me to map it as a car park. Further down the road the local co-op has about a dozen parking spaces in front of it. What about a pub car park? Most pubs have them. Or a large superstore or a retail mall of some description? The latter two I would almost certainly include.
In my opinion, I would not map each car par that is related to a shop or a pub when it is relative small (e.g. less than 20 cars). Because that wouls spread to many elements in the map. And for normal shops it’s not so important whether they have a parking lot.
when you have big supermarkets or malls with really big parkings, it is more obvious to map them.
In the distant future they will be mapped. Very distant for some areas, but anyway. If sufficiently many users add the “capacity” tag and bug the map style sheet maintainers about it (see “Trac” in the wiki on how to do that), small car parks could be suppressed until higher zoom levels.
But those are all quite large car parks. Would you (for example) include two parking spaces reserved for customers next to a Mom and Pop hardware store?