Apple is a luxury brand. They would likely be making a luxury car. People would buy it, among other things, for trendiness, prestige and social standing.
They're around 1/3 to 2/5 of smartphones in the United States [1] and about 1/5 worldwide [2]. (About 2/5 of people, worldwide, own a smartphone [3].) Meanwhile, Apple captures something like 90% of global smartphone profits [4]. High-end margin leaders sell luxury products.
All those services only really make money due to ecosystem lock in.
Unless you expect some iOS-centric reason to order an Apple car with a higher price, I can't imagine why this would be good for Apple.