Does a thing sorta car-shaped without wheels count as a car? This thing never even had a lid. (You could call it a car, I guess... Rectangular, and you can sit in it.)

Many people hope a legitimate sarcophagus, with an actual mummy in, might yet be found.

At which point of building a car separate parts become a car? And during maintenance (lets say engine replacement) is a car still a car? I'd say it is if meant to be used as a car again.

Right. So, is a stone box in a pyramid chamber that there is no evidence ever held a corpse, or even had a lid, and certainly will not have a corpse in the future, really a sarcophagus? It seems to depend on overconfident assumptions.

Given their experience, a decoy that looks like a looted tomb would just be good planning.