I was checking something in the boot earlier today and noticed that the inner ring of the tyre in there had about 1cm of water the whole way around it, and the edge of the wheel well had some condensation on the side closest to the seats. I also noticed a ring of mould where the tyre had pushed against the cover.

I stripped the carpet off and it look dry. The sides were dry, no water in the front of the car under the carpets, but I did notice some really old rags and a tea towel on the left side behind the carpet in the boot. I was wondering what the likely cause of this is?

Nothing was wet...

Model is the Ford Focus 2011 MK2 facelift.

Edited October 9, 2025Oct 9 by Twistedwheels

If there were really old rags in there and they were wet, a previous owner knew about it and put them in there as bodge fix to get rid of the car. How long have you owned this car?

1 hour ago, Neb_engineer said:

If there were really old rags in there and they were wet, a previous owner knew about it and put them in there as bodge fix to get rid of the car. How long have you owned this car?

Five years. The old rags were dry. To be honest, everything was dry, that's the weird thing. I checked the vent drains from the outside and no water came out. The felt didn't feel as though it was wet, and there's nothing that I can make out that is wet... 

It was literally just wet in the rim of the spare tyre itself, and some condensation around the edge of the wheel well. 

Check the bottom of the spare wheel well.  Someone may have removed or punctured the bungs in the base to let any water drain out.

If the sides are dry, the water is probably coming from the lights or the spoiler/tailgate.

Leaks can change over time as parts go through heating and cooling cycles, so a previous leak may stop by itself.  It may also start again in future.

1 hour ago, TomsFocus said:

Check the bottom of the spare wheel well.  Someone may have removed or punctured the bungs in the base to let any water drain out.

If the sides are dry, the water is probably coming from the lights or the spoiler/tailgate.

Leaks can change over time as parts go through heating and cooling cycles, so a previous leak may stop by itself.  It may also start again in future.

The lights and spoiler/tailgate were on my list! I saw those under common issues. The spare wheel well was dry, it was just the wheel itself that had a ring of whatever in the indent around the spare wheel itself, and a little bit of condensation on the top of one side of the wheel well. 

I assume that wherever it's coming from, it's being running under the carpet on either side of the boot wall as those aren't damp, and was being soaked up by the underside carpet on the boot cover as that's where the mould was. It didn't seem to be wet on top at the very least. 

Thinking of sealing behind the lights, and the welds around the tailgate/spoiler as people have mentioned online. Just wanted to see whether someone had my exact issue where it'd been purely limited to being wet on the tyre and underside of the boot cover.

It's always frozen on the inside in winter, so I assume that there must have always been a leak of some kind as I'm careful bringing water into my car. 

15 minutes ago, Twistedwheels said:

The spare wheel well was dry, it was just the wheel itself that had a ring of whatever in the indent around the spare wheel itself, and a little bit of condensation on the top of one side of the wheel well. 

The well will be dry if someone has punctured or removed the bungs, that's why they do it. 

For water to gather in the top of the rim, I would be fully expecting it to collect in the well first, and then condense up on top with repeated temp changes over days and weeks.

59 minutes ago, TomsFocus said:

The well will be dry if someone has punctured or removed the bungs, that's why they do it. 

For water to gather in the top of the rim, I would be fully expecting it to collect in the well first, and then condense up on top with repeated temp changes over days and weeks.

They look like they're intact to be honest... No punctures elsewhere either.