It's not like the US has that many either. It's not the kind of winner-takes-all network effects industry that attracts venture capital outside of the Musk reality distortion field.
Math was never my strong point, but AFAIK the "not that many" of the US is still a greater number than the zero of Germany.
When people talk about the "auto industry" of a country they typically mean passenger cars. Golf carts don't count.