Designed for modern, large-screen head units (up to 11 inches or more). Installation Guide for Carletter APK

Navigate to your car's Settings > Car Infotainment > About Device . Some units require a passcode (like 8878 ) to access hidden developer menus where you can change the default link software from "AutoLink" to "CarLetter".

Supports wireless Android Auto and Apple CarPlay connections, which some users find more stable than competing apps like AutoLink.