Potential subscribers in the New York City area are allegedly being turned away because of a lack of vehicles.

General Motors' seemingly innovative 'Book by Cadillac' service has allegedly struggled out of the gate, described as a 'major flop' by 24/7 Wall St.

The report criticizes the program's 'poor' customer service, claiming that interested customers first receive no immediate response. In New York City -- the first launch market -- some potential subscribers are said to have been turned away with a message suggesting they are being put on a waiting list.

"At this time, there have been more requests than the number of open subscriptions," the generic response allegedly says. "When a Book by Cadillac subscription becomes available, you will be contacted about the next steps."

At $1,500 per month, the service is aimed at attracting a wealthy demographic that is also the group of customers most likely to shun the brand for such missteps.

Cadillac promoted the service as a way to experience the brand's entire portfolio without any time commitment or mileage limits. Participants simply pick and choose whichever vehicle they want at the time, perhaps an Escalade for skiing in the winter and a CTS-V for the summer. The cost covers insurance, maintenance and detailing.

"Book by Cadillac is an innovative new option targeted at a growing class of luxury drivers searching for access to various cars over time, dependent on their individual needs, coupled with a hassle-free white-glove exchange," said Cadillac marketing chief Uwe Ellinghaus.