B+ motorhomes

For what it's worth, water runs down hill and seeks the lowest straightest path, even though the path may not seem logical, the water knows the way. Time for a bit of investigative looking. First, dry everything out with towels and a hair dryer, be careful not to burn anything with to much heat. When your sure everything is as dry as possible, get out the water hose, start a small stream and with someone inside while someone else works from the outside, SLOWLY wet the surfaces starting as low as possible and gradually work your way up till the leak starts to flow again. Work carefully and slowly playing the water stream gently over any possible entrypoints. Water from rain will start high, run down the outside until it reaches an opening and then flows inside and continues to run down till it is stopped by the flooring or something else like the ground. Another trick is to go out at night with a strong narrow beam flashlight and a friend and move the beam around all the openings looking for any light intrusion either going in or out. Door assemblies are notorious for having air and sometimes water leakage around the door. They will find it, biggest problem is taking the time to diagnose the problem. Good luck, I'm sure you will be able to stop it.