"Because this is a brand building act, we expect it will build over time rather than instantly driving showroom traffic," Buick said in a memo to dealers describing the program.
One of the dealers involved in the Phoenix pilot was Henry Brown, chairman of the Buick-GMC National Dealer Council and owner of Henry Brown Buick-GMC in Gilbert, Ariz. He said fewer people than he expected took cars for the night but the offer made a favorable impression on most customers.
"It's more of an image builder," he said. "Some people can't believe that Buick has the confidence to send them out in a car without a salesperson sitting next to them to tell them how great the car is."
Brown said that the customers who took advantage of the extended test drives were far more likely to buy the vehicle than a typical test-drive customer.
Dealers who sign up for the program must already operate a fleet of loaner vehicles for service customers, which GM calls its Courtesy Transportation program. GM has expanded those fleets dramatically over the past two years across the Buick-GMC and Chevrolet sales channels by enticing dealers with financial incentives to earmark vehicles as courtesy loaners.
GM dealers also bulked up their courtesy fleets last year to help manage the influx of service work from last year's record safety recalls.
Brown said many dealers in 2003 were reluctant to take cars out of their inventory for the 24-hour test drive. This time, he said, "we already have courtesy transportation vehicles that are qualified and ready to go."
Regardless of the intent of the test-drive program, Buick could use a sales lift. Its U.S. deliveries fell 6.3 percent through the first six months of the year, to 106,314 vehicles.
Aldred acknowledged the struggles of Buick's car-heavy lineup in a market that's tilting toward crossovers. And the cars in Buick's showroom -- the Verano, Regal and LaCrosse sedans -- are nearing the end of their life cycles. That leaves two crossovers to carry the load: the hot-selling, petite Encore and the full-size Enclave, which also has gotten long in the tooth.
A recent push to boost shipments of the Encore from a GM plant in Korea by 50 percent should bear fruit in the second half of the year, Aldred said. And he's encouraged by improving brand-image metrics, momentum that he hopes the 24-hour test drive will sustain.
"In terms of brand health," he said, "I think we're laying a very solid platform."