For me it's obvious why they all were most likely red.
In comparison:
UK Caros were mostly blue, with less common colours being aforementioned red, as well as white. Most surviving examples are pickups
Also, the Polonez Caro in Beijing Classic Car Museum was manufactured in 1993 and arrived in China in 1994. Did Chinese government import used cars, too? Or maybe this example was manufactured in very late December? Or maybe even this was a private import?
I have no idea, in the article (carnewschina dot com) says "The vehicle belongs to a employee of the museum and is still being used as a daily driver". Thing about private import back in the day is that it's a unlikely chance of happening. (Unless you have a good relation the the officials)
Back to the Caro: about the photo you found on Baidu forums, if Polonez didn't have a Chinese number plate, i would mix that location with an Eastern-Central European neighbourhood :lol: :lol: :lol:
Also, Caro GLE's weren't officially exported as far as i know.