The reproduction plaid trunk mat I bought came with little pieces to go over the cut outs for the braces that the bumper bolts to. I assume they were actually not used originally? I also read I need to cut the mat off at the edge of the gas tank on the passenger side. How far forward does this cut extend? What color thread was used for the stitching? I know nothing about they types of thread but pictures I've seen seems to show a heavy thread. Is there a thread size I should get?