Some fences need to remain. Take barbers/hairdressers, for instance. It turns out that a barbershop can be a great place for spreading head lice. You want your barber/hairdresser to be trained to prevent that. That's part of what their licensing is about.

So, are there any aspects of being a car dealer that are worthwhile fences? Offhand, I can't think of any, but that doesn't mean there are none.