Keeping true to my comment I made nearly 3 years ago, I attempted to extract the driver quotes from the PS2 files. And it was a success, as I found quotes for all drivers, even unused ones such as when engaging in Car-Fu battles (at least in the PS2 since I haven't tried the Wii) and for PS2 characters (Kakkoi, Scooter etc.), Rival battle scenes and UI Chara Select quotes.
Do you have the 3D models of all 5 PS2 characters (Scooter Dickey, Kakkoi Teppodama, Sam Storm, Sweet-Tooth Jangala and Chim Chim)? I have the models of the Wii version only, and I would like to have all 25 models of both versions.