Dealers paid a fee for the lead if a buyer clicked to contact them and get a quote, that fee said to be a little higher than with traditional channels. But dealers didn't like the fact that all of the contact options were anonymous – a shopper got a disposable e-mail and phone number that was active only as long as the shopper responded; after six unreturned phone calls, for instance, the phone number would no longer be valid. That hampered dealers' follow-up opportunities.
The service actually shuttered at the end of January this year, but Google still has plenty of tools like surveys and mobile - it's just that none of them so overtly make the search giant a paid middleman between dealers and buyers. Search for a car on Google now, and you get an info box next to the results with information on the vehicle, but no options in that box will lead you to a dealer.