With the amount of time elapsed, lack of information, removal of her face and the vehicle from billboards, I strongly agree and share, "just your opinion."
Just my thoughts, as well.
From: http://police.illinois.edu/search-updates/
The FBI has announced that investigators located the black Saturn Astra used in the abduction of Yingying Zhang.
The driver is not some random innocent. This car was observed multiple times trying to lure young women into his car. I don't really understand all this rampant speculation about her family, boyfriend, trying to escape China (seriously? she's a top tier student with a full scholarship coming to further her education!), when there's a clear cut answer with multiple independent corroborations: a lone creep was trying to lure women into his car, posing as an undercover officer at least once, and finally succeeded with Yingying. Really, Occam's razor reigns supreme.