Prompted by Kevan's question about sealing his rooflights, I thought I'd share my tip.
The roof lights on later Carawagons are fitted using traditional windscreen rubber and filler strip. Unfortunately, even though I replaced the rubber with new when I restored my roof, they still leaked!
Not wanting to resort to what one or two other members do - throwing a tarp over when it rains

I remember using something called "Seek & Seal" back in the 70s to seal a windscreen which always seemed to leak (Fiat 500!)
However, my searches have come up blank so it looks like that product is no longer available, but I did find THIS STUFF which is very similar.
Using a syringe and a blunt needle, I injected it all around the seal and that seems to have done the trick

It looks like milky water, but sets clear, and seeps into any gaps it can find.
It's easier to do the rooflights with the roof down so the fluid doesn't run down the glass.
I've also used it to seal several roof rivets where the water seems to seep through

Hope that helps some of you.
Cheers,
Robin.