What if Mercury was positioned as Buick's main competitor in the Chinese domestic market.? it's exactly the same sort of marque, with a long history, albeit it shorter than Buick's. This could be their dedicated luxury compact offering, the Monterey. all CDM Mercurys would be hybrid and awd.

base photo an 'upmarket' version of the Corolla. car would not be Corolla sized though.

Imagine Monterey as slightly longer and lower than a Milan, with more rear legroom.:

I could definitely see that work in the Chinese market, not so much in the American market.