We noticed a musty smell in the van and couldn’t work out where it was coming from. After narrowing it down to the rear of the van, I removed the partition between the bed area and the rear doors. At first, I suspected the door seals, but they proved OK with the hose pipe test. On closer examination of the roof, I found a repair where what I can only assume was an amber light had been removed, and RTV had ‘repaired’ the screw holes. I used butyl tape after thoroughly cleaning the areas to seal over the holes. Also, I found that the nuts securing the rear brake light / reversing camera had vibrated off! I rescued these, and it’s looking watertight. I also removed all the insulation over the back doors, which was holding a ton of water. This will be replaced after I can confirm all is dry and the leaks are truly gone.