On Monday, 5 February 2018 19:52:39 UTC, wrote:
I finally got the right tuit to investigate how the boot of my wife's
i20 was getting wet. Having removed the right boot trim panel and played
around for ages with a hosepipe I noticed that the offside roof trim
(the plastic strip that runs each side of the roof panel) is slightly
loose and I think this is where the water is getting in. I can't find
anything to tell me how the trim is held or sealed, or how to remove it.
Is anyone here knowledgeable about i20s? If not I'll have to take it to
a bodyshop.

I had the same problem and after hours with a hose I found it was only leaking when I sprayed the roof trim just behind the drivers door. I covered the roof trim on the drivers side with duck tape for two weeks and no water got into the spare wheel well despite very heavy rain over that period. Took the car to my local body shop and they removed the old sealant where the roof and side panels are spot welded and applied a new bead of sealant and leak is now fixed.