Consider a group of 10 friends (Jack, Mike, Harry, Peter, Ian, Ted, Stoney, Julie, Maria, and Samantha) named 'Spartans' in some residence colony. They have collected money and bought a brand new car.
Is this structure possible?
Wow, what a sexy car that is
Yeah! That's Spartans'
Ah, I mean Jack, Mike, Harry, Peter etc's.
Oh! Are they Spartans? I did not know.
Or it should be ...
Ah, I mean Jack's, Mike's, Harry's, Peter's and etc. or
Ah, I mean Jack, Mike, Harry, Peter's and etc.
I referred to lots of examples and found that etc. is generally applied to the nouns, verbs and almost anything but found no instance where it's used for the noun's possession.