Sure there is XL's jap version. Trust me. I have this version.
But I've never heard of jp. ver. of W'O. I assumed there would be one. All in all, this was one of the launch titles of PS (a second launch title as far as I remember....the first one was Ridge Racer), and since Playstation came from Japan, it would be just unfair towards the japanese not to have this game.
And BTW - nice artwork on the manual. And tell us if the credits and the congratulation lines after finishing the firestar in championship are in kanjii. Or if there is some kanjii anyway. Wipeout + japanese culture rocks!!