The multifunctional digital interface integrates interfaces for MP3, USB stick, SD storage card and mobile hard disk. It may transform the audio file into melody with the on-vehicle audio equipment to meet the customer's needs of fashion, convenience and pleasure during traveling. Besides, the instrument panel cover leaves sufficient space for modification, addition and replacement. Customers may, as they like, change the cover into cooler and more fashionable one with all kinds of effect, such as multicolor, crystal, pearl effect.