assorted punitive duty regulations brought in to protect the uncompetitive native car industry, meant it made sense to make locally.... also, shipping manufactured vehicles around the world is inefficient and costly , relative to shipping piles of bits.... then of course there's the sea salt , and extended delivery time on custom options.
one can only hope China never really gets to grips with car manufacture....
They are already making inroads and are selling globally Google "Great Wall Motors", yes they sell in the UK and other European countries, There are also other Chinese manufacturers who are building a presence in the UK and Europe. So like the Koreans a few years ago, they are on their way.
Like Korea they will not match European manufacturers for quality, design or safety, they will be sold on price, but they will catch up. Their domestic market is huge which is where they earn their bread and butter, which will provide the R&D money.
It is inevitable that some European manufacturers will merge / disappear. The obvious casualties are Peugeot, Renault and Fiat as their cars are in no-mans land on price, design, street cred and reliability. GM Europe are also by no means secure.
Local tastes dictate that care are localised for particular markets. What tends to happen with their mass market models is that they are variations of a core floor / platform.