Have you ever seen that a very important setting is missing in the Japanese version? Yesterday I examined all 3 versions and that's when I noticed it for the first time. The "sensitivity" option under the steering wheel is missing. This is the most important option for me, without it you just look at the stick and it starts to drift xD
However, you can set this setting in the NTSC-U or PAL, and then switch to the Japanese version and have the same settings saved. Even if you drive and save times or the championship, your "sensitivity" settings will not be overwritten. So I think the online match can start