Very dangerous.
With fewer dealers, the temptation for the agencies is to rely upon TV entirely, cutting out radio. Agencies love TV--higher rates=bigger commissions-less work in placing the schedules (e.g. 2 or 3 TV stations as opposed to a dozen or more radio stations in a given market).
Often the dealers got us the agency buy--since the smaller, rural dealers would be more active on the "dealer's boards" that advised the manufacturer on the placement of co-op money--and they got very little benefit from money spent on TV and newspaper ads. Especially where their region includes a large city 70~90 miles away, and all the advertising dollars ended up there.
Once "Obama Motors" is created out of the wreckage of GM and Chrysler, there will be no more rural dealers except for Ford.
But then, the second dip of the "W" recession created by this administration will take "General Chrysler" into a real bankruptcy anyway. Leaving Chevrolet/Buick as much smaller company and Jeep being sold off to someone else. Fiat will flee, getting the "punto" once again that Americans won't buy glorified golf carts until gas hits $6 a gallon.