The EU is a customs union. Import tariffs are set by the EU, not by individual member countries.
The 10% import tariff applies to vehicle imports from countries that do not have a free trade agreement with the EU, including the US and China.
Imports from countries such as South Korea (Hyundai, Kia) and Mexico (Ford) are exempt from the tariff thanks to bilateral FTAs. Japan also has an FTA which phases in over the next decade.