Another oddity related to unlocking something in Mario Kart 7 is shown below:
When the game displays the gift graphic, if the player goes to the previous screen, and then advances forwards, the menu's music will pause for a few seconds, and then it'll restart.
In Mario Kart 7, when you unlock a new vehicle part, it appears as a gift icon in the selection menu until you open it
However, if accessing the Mario Kart Channel’s kart customization screen beforehand, it'll be shown as unlocked before you open the gift, spoiling the surprise