Thanks, both good idea's. I was thinking behind the backrest (under the cover) and the behind the top of the back rest. It has a small area. I will check my local marine store for covers. I hate to just pop two holes in.
I was worried that the bottom would lift up spray when raining. Like on a SUV when its raining (notice the back window is always dirty).
I think that we are all still on the edge of our seats wondering what you are hauling around in the tourpack that needs to stay cooled. This summer, I froze some small bottles of orange drink and put them in a small insulated cooler in the tourpack. I figured they would melt rather quickly in 90 degree temps, but they just didn't thaw. At the end of a 300 mile day, I still had frozen drinks when I got home. Anyway, if you are really looking for something for airflow in there and seeing that you live in PA, I would think that the only time you could need the airflow would be in hot, dry weather. I'm in PA too and the rain pretty much cools down any hot day(not that we get that many of them). Why not put some sort of vents in that can be water tight when they are closed, and why worry if it's not raining? Maybe some pop-up mini hood scoops with a rubber seal around the edge to water seal them when closed. Or cut some holes the size of some rubber plugs you find and pop the plugs in when you want it sealed from water. Anyway you look at it, this sounds like a project I sure wouldn't want to undertake. I did just come up with another idea. If you really want to put the money into doing it, you could put some mini air scoops wherever you decide to place them, and the holes would be out of sight from the outside, being covered by the scoops. Just make sure you have rubber plugs that you can close off the holes with from the inside for rain or washing. It sounds like you are going to have some paint matching work ahead of you. Good luck.