Options/Howto - Audio - Video - Save Data - Settings/Speed
I cant find a menu to turn it on at all.
tbh, i only played it for like 5mins and that was right at it's release.
Look in your game manual. lol :D
i never noticed any differance of virtua tennis at all with m+ and cudnt find anythin in the settings
best game so far for me with m+ is grand slam tennis!!