I finished the story first. Didn't do any races (I hate games with racing in it), then I began clean up using the saves from this thread. I started with the "legomsh9" file first, because I was dreading the races and saved that for last.
But when playing the game as usual, the trophy which included completing the race for a gold brick, popped. Doesn't get any better than that. I even got the character trophies to do the same as well. So I didn't have to use the "LEGMARCAR" file because the Platinum popped.
Now mind you, I only want the legit look as well, so I would turn off the PS3 off when one trophy pop, and reloaded the save from the USB stick that I kept in the console. So when I turned the console back on, I just overwrite the save file with a "fresh" one. A when the game load up, rise and repeat.
Worked for me.