Best way to find a leak is to either have an air test done, or do it yourself. Pressurize the air inside the rv and use a spray bottle with soapy water around the outside to find where the air leak is.It will blow bubbles when you find it. This is probably where the water is getting in. Saw a thread on how to do your own test. Cut a hole in the side of a storage tote to accept a leaf blower. Turn it upside down over an open roof vent. If all the doors and windows are closed, it should pressurize the rv enough to find the leak. Have not tried this yet, but in theory it sounds like it should work. Good luck.