I bought a Japanese domestic vehicle recently. It has the JBL car audio system. Please send me a link on how to install OSM on it? i’m sure you must have discussed this topic previously.
It would be helpful to know whether the car you bought was unbranded (as implied by your use of the non-specific term “a Japanese domestic vehicle”) or has a real make and model, so we can know exactly what navigation system (if any) it has. A “JBL car audio system” sounds like it’s audio only.