Now the "Audi bicycles" on the market are not customized by the public, so they are not OEM. It's just that some brand-name bicycle manufacturers use Audi's trademark (because Audi doesn't register a bicycle trademark, it's not infringement) to make money by taking advantage of people's trust in Audi. The technology and configuration of this kind of bicycles are uneven, but they are generally low. Imagine that the giant Merida, a manufacturer with its own brand and relatively high technical level, naturally does not have to take other people's brands. Therefore, those "fake" Audi bicycles are not cost-effective, so it is not recommended to buy them.
By the same token, those BMW, Lamborghini and Porsche bicycles are fakes.
The bicycle industry has its own bicycle brand, so there is no need to use those "deck" goods.
Have a nice trip!