Apologies for starting a new thread on water seepage; but I've checked (and tried) other discussions without solving my problem - so here it is.

I have a 2001 Octavia Elegance Estate. It has never had a water seepage problem in its history, or been repaired. Two days after it was returned from a service last week I noticed a small damp patch on the underside of the rubber mat in the passenger's footwell.

The car has been into another dealer (at some cost) who have soak tested it, refitted pollen filters, cleared out air con plenum chamber, refitted passenger door seal and all the other solutions. But the damp patch recurs.

Water doesn't appear in the car when it is raining heavily or when driven in rain. It only appears after the car has been stationary overnight, and then not every night. The damp patch is not major, the carpet isn't soaked, it is almost like condensation. It appears in the flat area of the passenger footwell to the rear close to the box section that runs under the front seats. There is absolutely no sign of moisture near the heater box or the other suggested culprits.

I'm at a loss (cerebrally and financially) to know what to do next. Any suggestions are very welcome.

Just a final comment. I had cause to contact Skoda UK's customer services about another problem arising from the service. What a total waste of space the customer services department at the UK head office is. Emails are never answered, phone calls never returned as promised. And they have the cheek to send me a card saying 'Your opinion counts'.

Can you get access to a car lift? If so, check for a misplaced drain block.