First discovered by MacRumors, Apple seems to have secured the apple.car, apple.cars, and apple.auto domains, all of which could obviously be related to the company's rumored entry into the car market. Though domain records can be falsified, it's unlikely here: the domain WHOIS entries make reference to MarkMonitor, an intermediary that protects brands from domain squatting.
Assuming they're genuine, there are many plausible explanations for the registrations that don't directly involve the development of an Apple car — Apple, as with many large companies, registers a wide variety of domains as a proactive measure against squatting and customer confusion. (It owns apple.audio, for instance.) And then there's the fact that Apple is already in the car business as it ramps up the deployment of CarPlay, its in-car phone connectivity system.
Still, if you're going to make a car, apple.car is a great domain to own.