 According to the findings, plug-in buyers expect more from dealers than conventional buyers, including product knowledge and support that extends beyond traditional offerings.In 2014 "Consumer Reports" published results from a survey conducted with 19 secret shoppers that went to 85 dealerships in four states, making anonymous visits between December 2013 and March 2014.The secret shoppers asked a number of specific questions about cars to test the salespeople's knowledge about electric cars.