In classical marketing terms, Ed is right about the car being the product or merchandise. The dealership is the end of the distribution channel, the retailer. That isn't to say that retailers don't add value to the product, they must. However, marketers generally don't refer to the value added by sales efforts as a product. The service of vehicle repair is a product, the service lane is distribution. Having said that, the lines can get a little blurry.
A retailer of bottled water at the beach adds place utility. Nothing more, but it is worth a premium. Walmart doesn't add value any differently than its competitors, but it does it for less. If you sell cars at a premium, then you need to be able to demonstrate the added value. If you can't demonstrate it to the customer in the age of transparency and choice, then you need to think about selling on a low-priced transaction basis.
Some retailers actually make the product. Starbucks and Cold Stones were mentioned. Both of these companies add value to the product, primarily buy making it custom. They both try to add value beyond the product: clean restrooms, atmosphere, friendly service.
I don't think anyone is wrong here, it is more a question of vocabulary. In the pop-culture that surrounds marketing, the vocabulary constantly changes. In classical marketing terms the word product means what it has always meant.
All this misses Alex's fantastic point. If your people don't know how they are adding value, then they will not be adding much of it and they will not be fulfilled. To Joe's point, enhancing confidence adds value, but I think some stores need to be realistic about how much of this value they actually deliver and what it is worth. Getting the shopper into the right vehicle with the right mix of accessories, financing, service contracts, etc. is also a job worth doing and being rewarded for. Rarely are the differences in vehicle prices equal to the cost of buying the wrong car and having to switch again. Proper matchmaking is just one way dealers can add value, but you need to be honest about whether or not you are in the business of proper matchmaking. I doubt anyone at a high-end dating service ever put a spiff on Ugly Betty because she had been around for 90 days.