Why do Class C's always leak in the front upper bunk area?

Yes, they are notorious for front bunk leaks. Many MFG's even quit putting windows on the bunk area, but still, they can tend to leak. The best think IMHO to do with a C if you like them is to keep them in covered storage and so that it won't be victimized by the elements all the time. Does it stop leaks? No, but water won't get in it if it's covered under storage. It's a great way to "stop leaks" and preserve the coach.