We are stuck between a rock and a hard place right now.
I could see no point in getting my bellows changed for another 04S set. And possibly, based on the dealer telling
@Fish111111111. they weren't going to replace his bellows for a second time, VW have concluded the same (yet to be verified as
@Fish111111111. is trying to find out what is going on.)
So what else are we supposed to do if we don't want to reject our vans?
If a waterproofing spray on the seams fixes the problem in the short term and doesn't cause the material or stitching to fall apart, then happy days for now.
VW will have to come up with a permanent fix as it looks to me as though the problem is getting worse, not better. If they determine that a waterproof spray is the permanent solution, perhaps with a top up at each service, then I'm fine with that. If it stops the leaks, then the bellows are working correctly.
My Paramo waterproof jacket is one of the best walking coats I have ever had. It is now at least 15 years old and is used regularly. No leaks in even the heaviest of downpours. It doesn't rely on taped seams and a waterproof backed material in its construction. But it does need a periodic wash and reproof with Nikwax to keep the water out.
If the bellows on my Cali need a quick top up every year with Aqua Tex or Fabsil, and VW get off their backsides and say it is OK to do so, then I'm happy to do this, or to let them do it.
Personally, I would rather apply the waterproofing myself then I know it has been done carefully and thoroughly.
At the end of the day, surely all we want is a set of bellows that keep the water out when it rains.