He stumbled upon a setting that looked like a speech bubble.

The keyword is the giveaway. This is the brand name Pioneer uses specifically for the Japanese domestic market (JDM).

As noted in similar Pioneer interface guides , many Carrozzeria models—which are primarily made for the Japanese domestic market—don't have a full "English" mode. Instead, they offer a "Partial English" setting that changes the navigation prompts and basic buttons while keeping the deep system menus in Japanese.

The AVIC-RW300 is known for its balance of high-end navigation features and multimedia capabilities..