Many car subsystems interconnect with each other and the in-vehicle infotainment (IVI) system via various bus topologies. The exact bus type and protocols vary widely between manufacturers (and even between different vehicle models of the same brand); examples include Controller Area Network (CAN) bus, Local Interconnect Network (LIN) bus, Media Oriented Systems Transport (MOST), as well as automotive-grade Ethernet and TCP/IP networks such as BroadR-Reach.

The Android Automotive hardware abstraction layer (HAL) provides a consistent interface to the Android framework regardless of physical transport layer. This vehicle HAL is the interface for developing Android Automotive implementations.

System integrators can implement a vehicle HAL module by connecting function-specific platform HAL interfaces (e.g. HVAC) with technology-specific network interfaces (e.g. CAN bus). Typical implementations may include a dedicated Microcontroller Unit (MCU) running a proprietary real-time operating system (RTOS) for CAN bus access or similar, which may be connected via a serial link to the CPU running Android Automotive. Instead of a dedicated MCU, it may also be possible to implement the bus access as a virtualized CPU. It is up to each partner to choose the architecture suitable for the hardware as long as the implementation fulfills the interface requirements for the vehicle HAL.