There are 12 rivets, I added mine so there were no holes to start with and no pattern comes with the panel. It takes a lot of measuring and marking before you drill the first hole to make sure it's in the right spot. take your time and it will look great. Measuring from the left side the holes are placed at 4 3/16,
16 5/16, 27 5/16, 38 5/16, 49 5/16 and 61 5/16

Here is a picture, they are hard to see because I rhino lined after putting them in