I bought the Japan prologue long ago when it was not available in the USA. Now i would like to buy the US version of the game. Does any of the information transfer over or is all of it lost when you install the game?
Unfortunately your save file will not be compatible the the US or EU version but if you want to have all the cars again then the only choice is to download a save file.
@OP: Different versions of GT5 Prologue have region locks within them, that means a particular version game save, say JP, can only apply to that particular version (JP game).
Therefore, unfortunately, if you wanna get all the cars you owned and the events you won in the JP game, you gotta play through the US version once again to earn those.
I bought the Japan prologue long ago when it was not available in the USA. Now i would like to buy the US version of the game. Does any of the information transfer over or is all of it lost when you install the game?
Best thing is just to Download some one else SAVE data with all events completed and all cars. That way you don't have to go through it again. I Did it.