Well, I now have a new 12 month ticket on the ZS. Flew through with only 1 advisory (first time this has ever happened to me!). And that is the back box is starting to rot. Now, the problem I face is that it isn't a standard back box (which I have only just found out) and I don't want a standard one as I like the sound this one makes. I want to know what Back box's are out there on a budget as it's the first time I have ever had to replace the back box.