This app note from Maxim Integrated describes the design and system challenges associated with USB chargers in automotive applications. Link here
Recent advancements in the automotive infotainment market demand high-efficiency and low-footprint power delivery (PD) solutions. The inclination towards a reduction in bill of materials has driven USB power applications to integrate more features and responsibilities into a single IC. The proliferation of battery-powered portable devices has resulted in an increase in the number of USB receptacles or ports in an automobile to charge the batteries of the devices.