I have them on both sides! I think that this car got left with the top down a few to many times, and the water never fully dried out, leading to condensing in that spot, and rusting it out.
It wasnt really a "hole" by iteself at first, just a ton of rusty metal. I started to "clean" up the rust and eventually got it down to that with just a screwdriver and a stainless steel brush.
I am not shure on what to do, but I think some cutting and welding in a new piece would be the best way.
I also got a good deal on a Racing Beat Header recently, pics as soon as I get it shipped!