Here in MI, there are TV stations that have segments like "Help me Hank" where you can contact them with a consumer issue and they report on the issue and intervene on the consumers behalf.
Maybe you have something local like this where you could contact them. If you do, I would email them and copy the person at the dealership that you are working with....I am sure they don't want bad press to effect their sales...
http://www.clickondetroit.com/help-me-hank