Car subscription services have begun to gain more widespread attention with launches such as Care by Volvo and Porsche Passport. Before both of those services, Cadillac arrived on the scene with its Book service, which launched early this year. Following a pilot program in New York City, Cadillac announced on Monday that Book will expand to pilot programs in Los Angeles and Dallas. 

With the expansion announcement, Cadillac also rolled out a few changes from when the service first launched in New York City. Foremost, the core of Book remains the same: for a flat monthly fee, subscribers gain access to a Cadillac vehicle and it includes insurance, maintenance, no long-term commitments, white-glove delivery, and detailing services. At launch in NYC, Cadillac included only V-Series performance cars and its range-topping Platinum trim vehicles. Now, Cadillac will add Premium Luxury trim cars to the fleet and the CT6 and CT6 Plug-In will join the lineup.

With the changes, the brand has also bumped up Book by Cadillac's price from $1,500 per month to $1,800 per month. The one-time $500 registration fee remains. That's still $200 less than Porsche Passport, which starts at $2,000 per month, but Porsche also offers a more premium tier for more opulent and performance cars at $3,000 per month.

Cadillac also said it has added additional vehicles to the NYC fleet to meet growing demand for the service.

Elsewhere, Cadillac also launched a Book pilot program in Munich, Germany, and more pilot programs around the globe may launch in the near future upon further consideration.