Translation:Is this your car?
Thr inconsistent translation of 你们 as "you guys" and "you" is very frustrating in this app.
There is no possessive marker for 'you guys' but I agree Duo should stick to just 'you' for both singular and plural.
The most literal translation of your answer would be "这部汽车是你们的吗？" But the concept is the same. I think you can try to report it.
你们 means "You guys" right? So shouldn't the correct answer be "Is this your guys' car?," not "Is this your car?"
Seriously, "you guys" is really a bad translation.
你们 is the plural form of 你, English use "you" for both single and plural forms. And Duolingo certainly uses a very misleading way to translate 你们.
Wh... first of all, "slang" is no less English than the "official" stuff. (I know we can't have all the slang on here, but that leads to my next point...)
Second, especially in this case, "you guys" is a rather common way to express this in (at least American) English.
And third, no one's "imposing" anything -- we just think that such a common way to express in English this important distinction in Chinese should be accepted.