Ashley Sandall recently set aside the keys to her Porsche sport-utility vehicle for three months to try out a few Cadillacs. When the Caddy she was driving became boring or proved too small for her weekend plans, she ordered up a different model with her smartphone and it would arrive the next day.
Ms. Sandall, a 35-year-old fashion executive who lives in New York City, said she was impressed with Cadillac. She used the brand's brawny Escalade SUV for trips to the Hamptons and a football game in New Jersey.
"It was great to have your pick of the vehicle best suited for what you're doing," she said.
After participating free of charge in a three-month pilot of General Motors Co.'s (GM) new Book by Cadillac subscription plan, Ms. Sandall said she is considering becoming a full-time member when it is time for a new vehicle. For $1,500 a month, the program covers ownership costs and lets members trade in and out of Cadillac's 10 models up to 18 times a year.
The effort is the latest experiment by a car company to test whether people are willing to treat personal transportation like a Netflix account, where temporary, on-demand access outweighs the benefits of ownership.