Dealer groups have some fairly strong lobbies in some States.
Then again, dealerships make their money in the "back end": Service & Parts mostly, and at some, their Body Shops.
So if the dealers see it as less Sales Dept. overhead, but with Customer access, they might swallow the plan.

Last time I bought a new car, I had fun toying with the Sales guys for a couple weeks, because I had options.
I'll probably never buy a new car again, but that was such a sport when I was holding the cards...