It's done using FBML (facebook markup language) so if you have the inventory feed and someone who knows FBML and car website development you can create any cool app for car dealers. Service forms would not be a problem.
DealerRater has an inventory listing tool that is free if you are a Certified Dealer but the GOSO application is much slicker and has direct integration to dealer site. Dealers can drop in their own custom tabs to match their website without a third party, if they had someone on staff that knows HTML.
The key thing is to determine how to train Facebook users to click on the TABS for different functions...and then to see how much activity develops. Overtime, consumers could prefer this way of browsing cars. It's so early in the game to see how much traction this gets but I love the way it looks, feels and so they are in a great path.