I'd sort of agree but when you stop producing vehicles domestically and rely on foreign manufacturers building cars in your country you lose a lot of the surrounding infrastructure since much of the design and testing is done abroad.
The ability to produce a car and similar heavy-industry type production is a strategic asset (which is I think one reason why the French government has been so supportive of it's native car industry for so many years even when French cars didn't sell well outside of France).
It's a hard balance, support an unprofitable industry to protect a capacity you might one day need.
If I recall correctly the US has(had?) a policy where american flagged cargo ships that mostly traded in and around America had to be built in America, this made them much more expensive but kept the major ship yards in business as it was seen as a bad thing if that capacity was lost.