An aftermarket vehicle head unit integration cartridge for use with an aftermarket head unit is provided. The aftermarket head unit preferably includes a dedicated slot for insertion of the cartridge. The cartridge preferably supports communication between a plurality of electronic components in the aftermarket head unit and a plurality of electronic components in the vehicle. The plurality of electronic components in the aftermarket head unit may include, for example, an audio processing system, a video processing system, an analog I/O and/or a digital I/O, and/or a plurality of electronic components. The plurality of electronic components in the vehicle may include an audio system, an analog I/O, a digital I/O/databus, and/or a steering wheel control unit. The cartridge may include a flashable memory for use in reconfiguring the cartridge. The cartridge may be configured to capture and condition the signals from at least one of the plurality of the vehicle-based electronic components. The conditioned signals from the vehicle-based electronic components may be conditioned for use by the aftermarket head unit.