There are holes in the floor/floors in/of your car!

1 Which is correct?
2 Do you call the base of a car floor?
Yes, it's a floor.
There are holes [in your car floor / in the floor of your car].
So cars have only one floor while houses have multiple floors? Weird.

Thank, CJ
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Well, a single-story house has only one floor. I suppose a double-decker bus has two floors. But where would you put the other floor in a car?
Optilang told me each room has a ceiling and I assumed, maybe he did tell me, that each also has a floor.
So, I thought there were at least two floors in a car, one in the front, another in the back. maybe the trunk also has a floor.
GG is using the word floor as "story" or "level". You are using it as "lowest surface".
Cars only have one floor (story), and they have only one floor (lowest surface), as far as I have ever heard of. Emotion: smile
Houses usually have one floor (story) or two, and they have as many floors (lowest surfaces) as there are rooms, I suppose.
(The entire car is conceptualized as having only one room, I suppose.)
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Thanks, CJ.