So, everything was all lined up for picking my car up from the restoration place on Saturday lunchtime, and I got a call in the morning to say that they were doing the valeting, and found that the spare wheel well was full of water exactly the same as what happened to tubs.
He asked if I wanted to sort it myself, or for them to look into it, but seeing as I'd never managed to track the leak down in tubs, I asked them to do it (also, after all the time it's been away I wanted it back sorted).
So they set away checking with a hose and found a clip where water was getting in when it was sprayed in a certain way, but in the mean time I'd called my usual mechanic who was going to be sorting the abs and mot to let him know that it was going to be late. He said that when he worked at honda, they had loads of jazz come back with this problem to the extent that honda had to extend the warranty.
The problem was the seam seal on the roof starts to fail, and small cracks appear which lets a surprising amount of water in. Honda used to have to strip the old seal out back to a certain amount, and redo it.
I got back to the garage and told them about it, and asked them to check in the channel under the roof rails. They had already sealed up any suspicious grommets etc, but they looked into the seal.
Turns out that there was a few little sections where it had cracked and small amounts of rust staring. The resealed the whole length just to be certain.
I'll put this as a sticky topic coz it seems to be a common problem starting.