The big 3 auto makers are all located in Michigan, USA. If they sold a vehicle direct, the sales tax dollars goes to the State of Michigan. Which means all the other states are missing out on *significant* tax dollars.
To force each state to get tax dollars, local dealerships were established. That way tax dollars go to the state the vehicle is sold in, rather than the state the vehicle manufacturer is located in.
I'm curious if this has changed at all over the last 20 years with the rise of e-commerce. For example, when I order a product on Amazon, do I pay taxes on that product for where I live (where the product is "purchased"?), or where Amazon is headquartered?