I work with car dealers on a regular basis. Most put up some form of this objection to me when we first meet: "I get calls from 10 new internet services a month, all promising me a unique service for my dealership." Here's what I tell them, buying an online service, or services, creating a website and putting your inventory online is like buying a ticket to a ballgame. Your at the game, part of the experience, but don't fool yourself, you're not IN the game, yet.
The link above is from a very popular blogger. He is linking to another popular blogger. That blogger posted a story about a poor experience he had at a northern California Toyota dealership. That post has been linked to thousands of times, and Dave Winer's post has been linked to thousands of times. And of course both original posts have been read by thousands of folks.
Do you think the auto dealership even knows this is going on? I'd bet big money they don't have a clue. And even if they did know what is going on, would they know how to effectively respond? Doubt it.
Getting in the internet automotive game takes more than the price of admission.