I was hoping someone w/ a C320 would see this and reply knowing how the liner goes in the boat.
I have a C320 but have not experienced your problem. In hard blowing rains, I do get some leakage around the overhead hatch in the main cabin, and I'll have to rebed that hatch this spring. If I'm there after the rain, I'll see itdrops on the table or cabin sole. If I'm away, occasionally, when I do come to boat, there will be just a little water in the bilge, which evaporates in a few days.
If you haven't done so already, you might direct this question to the Catalina 320 Internation Association. Lots of C320 owners there. Go to www.catalina320.com
, at home page, click on Discussion List and sign in to the discussion group list and ask the question about the leak. You don't have to join the association to take part in the discussion group.