In its push for the Apple Car, Apple has applied for 248 patents related to automotive development.

Apple’s bid to create the Apple Car, code-named Project Titan, is an open secret in the industry. Numerous automakers have been rumored to be in talks with the Cupertino company to build the Apple Car, although nothing has been confirmed. That hasn’t stopped Apple from pushing ahead, with Nikkei Asia reporting on the company’s trove of automotive patents.

According to the report, Apple’s patents fall into a number of categories, including battery and heat management, connectivity, self-driving, interior comfort, and communication and navigation.

It appears that Apple’s automotive-related patents began to increase in 2008, following the release of the iPhone. Many of the early patents focus on connectivity between phone and car. Later, however, the nature of the patents began to shift to ones more directly related to vehicle function, especially autonomous driving.

No one knows when an Apple Car may finally debut, despite plenty of speculation on the topic. More recent reports indicate the Project Titan team has shifted its focus from a limited self-driving approach to developing a fully autonomous vehicle.