While most design aspects of notifications are controlled by car makers, there are a few areas where app developers can influence design.
Car makers can customize many aspects of the notification experience in their vehicles, including styling of notification cards, timing of notification motions, and layout of the Notification Center.
App developers can influence notification design in the following ways:
- Background color (navigation only): Supply a background color for navigation notification cards, to be used at the discretion of car makers
- Icons: Supply app icons (for branding) and other icons as relevant, including avatars and large navigation icons (such as turn arrows)
- Accent color: Supply app accent color, to be used to color the app icon at the discretion of car makers
- Text length: Make sure text for notifications is as concise as possible
Keep in mind that notifications in cars are intentionally kept simple, to avoid distracting the driver. Fewer effects are supported (see technical note below) and car makers can choose to truncate any text beyond a certain length when the car is moving. Text that is not concise may end up being truncated and unclear.