whatabout all japanese companies that are producing their stuff in china these days. did they turn to shit now all of a sudden?
Products produced in china by foreign companies usually have quality standards thay have to fulfill. This means that if a german car maker decides to produce in China (like Volkswagen and BMW do for regional markets) there are chinese working in the factory, but there are german engineers and german machines. They use quality raw materials and have quality testing.
The cars are tested to german quality standards -- which is not necessary by chinese law. Same goes for japanese products. There is only a slight chance of a slip in quality because the products will be tested again inside the EU, in germany or Japan.
This doesn't go for illegally imported chinese fakes. Legit chinese products only fit the minimum standards of european laws.
Google chinese cars and read some reviews.

Now there's a saying:
You open a business in China with non-chinese management, then the same workers that produce for you will produce fake products with cheap raw materials in your factory after hours.
You open a business in china with a mixed management, the fakes will be produced in the building next door.
If you open the business with a chinese management, the factory that produces fakes will open across the street.
Whatever you do, China will fake it. This has happened to Siemens Transrapid Monorail Train, BMW, Volkswagen and numerous other companies. These fake products are cheap and dangerous, China doesn't care to mix dangerous lethal chemicals into toothpaste, protein powder, pet food, faked medicine, perfumes, whatever. You name it, you can get a fake in China.