After discovering the water ingress I have now noticed this little bulge on some trim. I'm hoping that someone will be able to tell me it's nothing to worry about and it's just a problem with a loose screw. I'm nothe best diy'er when it comes to doing things on the van and am reluctant to start unscrewing and peeling back trim unless it easy and straightforward
I forgot to mention that in addition to finding a leak I fell or rather my wrist gave way and I crashed onto the seat whilst putting the bed away and cracked frame under the bed. I'm hoping to be able to pick up a piece of 20mm square to repair that myself