Yes, it can. Any object can sit. Note that this is an idiomatic use of the verb, however. If an object is 'sitting' in a particular place, it usually means that a person has left it there. The implication might be that the object doesn't belong there, or that the person has left it there for too long. Or it could simply mean that the object is 'waiting' for someone to get it. Here are some more examples: "Those dirty coffee cups have been sitting on the table all weekend! When is someone going to wash them up?" When I got home there was an enormous bunch of flowers sitting on my doorstep. I had no idea who left them there. "Why did you eat that cake?" " Well, it was just sitting there, wasn't it? It would have been a shame to waste it."

Yes, it's correct. It's an idiomatic sentence. In this case it means 'parked'.

Yes, any physical object can "sit" when it occupies a place.