This allows you to extract and replace blocks, making it easier to merge aspects of saves or just manually hex them.
You can also edit 4 of the blocks directly via the editor.
Stats, this stores a few things but via the editor you can mod a table of stats. :O Stats in stats OMG.
Career, this will allow you to edit the rep and score.
RaceFavorites, this is just a list of 100 map names that are in your favourites list.

Cars are stored towards the end of "Career" so you may want to be hexing that one.